Twitter might rebound in the wake of Jack Dorsey’s reappointment as C.E.O., but the service is still in trouble. Photograph by Richard Drew / AP

It wasn’t that long ago that I—and many other people I know—would have argued that Twitter was more than just another social network. I would have told you that Twitter was more like a utility, a service so fundamental that I could imagine a scenario in which it was literally underwritten. Twitter needed to exist. A stream of those hundred-and-forty-character tweets was how you found the most crucial, critical, and thought-provoking stories of the moment.

When bombs went off during the Boston Marathon, in April of 2013, users sat glued to the feed, suddenly privy to something visceral and real, something happening. And Twitter provided the view, an unedited, unscripted look into the world as it changed, through police-scanner blasts, eyewitness reports, and grainy citizen-journalist photography. It was raw, but it was streamlined.

But cracks in Twitter’s façade had been showing already. Changes to the product made it hard to follow conversations or narratives. A lack of rigor in verifying reliable sources made information suspect or confusing. More troubling was the growing wave of harassment and abuse that users of the service were dealing with—a quagmire epitomized by the roving flocks of hateful, misogynistic, and well-organized “Gamergate” communities that flooded people’s feeds with hate speech and threats. The company seemed to be wholly unprepared to handle mob violence, with few tools at its disposal to moderate or quell uprisings. Even its beloved celebrity users couldn’t be protected. In August of 2014, Robin Williams’s daughter, Zelda, was driven off the service after a series of vicious attacks.

Of course, getting noisy isn’t the only problem Twitter has today, though it seems to be one of the more pronounced symptoms of a company that has lost its direction, or, more worryingly (and perhaps more accurately), never had much direction to begin with. After a summer of turmoil and indecision—a summer spent largely rudderless after the resignation of the C.E.O., Dick Costolo—the company reappointed its co-founder, the Silicon Valley wunderkind Jack Dorsey, and signalled that, perhaps for the first time in a long time, Twitter could find its focus.

That focus would have to come fast. In the yearlong stretch leading up to Dorsey’s return, the number of active users on Twitter only grew by eleven per cent. Even more troubling was the service’s penetration in the U.S.: it remained completely flat for the first three quarters of 2015. Facebook has surpassed the company by orders of magnitude, but it’s hardly Twitter’s only foe. Instagram, WhatsApp, and even WeChat all now have more individual users than Twitter does. Snapchat has almost caught Twitter, too.

In Facebook’s case, the company has demonstrated its mastery of product focus and long-term commitment to user experience. While Mark Zuckerberg’s empire sent users sloshing to and fro on the seas of privacy invasion in its early years, the past five years have seen the company come to dominate and define the concept of a social conversation. If users get abusive on Facebook, they’re dealt with. If someone wants to wage a campaign of noise and intrusion, the repercussions are varied and plentiful. You may not agree with Zuckerberg’s “one identity” concept, but the fact that people have to register their real names has certainly made Facebook a much safer space in which to engage. That’s to say nothing of its mobile and ad offerings, which the company has finally paired elegantly, allowing Facebook to take an even larger bite of mobile-ad dollars. The company closed its latest quarter with revenue up a whopping fifty-one per cent year over year.

Meanwhile, a series of mediocre product changes at Twitter (such as the much-hyped but ultimately confusing Moments feature), a stagnant user base, and a massive executive brain drain have called into question whether Twitter can survive as a business. In the past week, the company has lost its vice-president of media, V.P. of product (to Instagram, natch), its head of the growing video service Vine (to Google), its V.P. of engineering, and its H.R. head. Unsurprisingly, the company’s stock has lost about fifty per cent of its value over the past three months.

But what should worry Twitter isn’t the value of its stock. (USA Today reported that, given its cash reserves, the service could run for another four hundred and twelve years with current losses.) What should worry Twitter is irrelevance, and there is growing data to suggest that that is where the company is headed. If Twitter’s real-time feed is its most powerful asset (and it is), it’s not difficult to see a future in which Instagram, Facebook, Snapchat, or even a newcomer like Peach (yes, I am citing Peach) focus enough on real-time news that they obviate the need for Twitter’s narrow, noisy, and oft-changing ideas about social interaction. Considering the fact that Kevin Weil, the head of product, left the company to join Instagram, it’s easy to imagine that service mutating or bifurcating into a speedier, more social platform for sharing links and having conversations. And, for many users—particularly young users, according to a recent survey—Snapchat is already their most important destination. We live in the Age of the Upgrade, and the generation raised on the Internet is the most fickle of brand champions: it loves something passionately, until it doesn’t. Then it moves on.

Ultimately, Twitter’s service is so confused and undifferentiated in the market that it’s increasingly difficult to make a clear case for its existence. There are a small handful of features Facebook might add, or a separate app that it could easily create (as it did with Messenger and the photo-sharing stand-alone feature Moments) that would provide a similar but more consistent experience, with vastly more reach than anything the company can provide today (or tomorrow, for that matter). This is especially notable to all of us in the world of media, the people who fill these services with highly valuable and hotly traded “content,” such as the piece you’re currently reading. Social media is a scale game or a product game, and Twitter is failing at both.

Yet there is something up ahead for Twitter, still. Another shift, another addition. Rumors currently swirl (and have been all but confirmed by Dorsey) that the service, best known and best loved for its tight hundred-and-forty-character limit—an economy that often forces clarity—will begin allowing ten-thousand-character Tweets with multiple images or video content. The hope is that, among the multitude of other storytelling platforms, Twitter can compete for the short- and long-winded alike. It’s a move that counters everything its users have come to embrace, and it is especially risky given that brevity is one of the few things that makes the social network unique.

That doesn’t mean that all hope is lost. There are hundreds of millions of dedicated users (I count myself among them) who still see tremendous utility in the service. The core ideals that made the product great are not lost, yet, even if they’ve been obscured. The directness and power at the heart of Twitter—short bursts of information that can make you feel that you’re plugged into a hulking hive mind—are still its greatest asset. The company just needs to find the right way to show the power of those connections to a bigger audience, and the value of that audience to advertisers and partners. Not a simple task, but for Twitter an unavoidable one.

In 2011, Jack Dorsey told the audience at the Wall Street Journal’s AllThingsD conference that, when people ask what Twitter is, “We don’t have an answer, and that’s O.K.” When he said it, he meant it as a positive: Twitter is what you make of it.

Five years later, it seems like the real question is, What has Twitter made of itself?