When The Ellen DeGeneres Show premiered in 2003, it was to low expectations. At the time, anyone who’d ever been on TV was trying to rebrand as a talkshow host and, for the most part, not succeeding (Sharon Osbourne, John McEnroe, Caroline Rhea – AKA Aunt Hilda from Sabrina the Teenage Witch).

A standup comedian-turned-actor, DeGeneres had a successful self-titled sitcom in 1997, when both she and her lead character came out as gay. This meant she played the first lesbian protagonist on a network comedy. But rather than hailing her as revolutionary, Disney-owned network ABC slapped an “adult content” warning on the show, advertisers withdrew their support and viewers sent death threats. Within a year, DeGeneres was unemployed, depressed and radioactive to casting agents.

It would have been easy to see the offer to present a daytime talkshow as a comedown, but DeGeneres turned it into one of the greatest second acts in showbusiness. Aware of what was at stake, she poured her energy and creativity into the programme, making it an extension of her persona: upbeat, empathic and wry without being snarky. She showed effortless charisma alongside guests as varied as Jane Fonda and Barack Obama, and her audience would coo when she talked about her wife Portia de Rossi and clap when she advocated for LGBTQ equality.

Now, DeGeneres boasts a net worth of $400m, a Presidential Medal of Freedom and 30 Emmys. But 16 seasons in, her show has lost its groove. Her post-monologue dance through the studio audience was once a signature set-piece, but she stopped a couple of years ago, without warning or explanation, and now lets her in-house DJ tWitch do the honours or plays a funny video clip instead. She seems a little weary, and the show does, too. Whereas she used to feature talented kids from viral videos in moderation, this year, 11-year-old Walmart yodelling sensation Mason Ramsey practically made her set his second home, and segments highlighting people or organisations in need who are surprised with a large cheque are well-intended, but feel rushed and formulaic, like a conveyor belt for poverty porn. Worse, DeGeneres too often gives in to her passion for pranks, such as asking Adele to act eccentrically in a juice bar, without seeming to consider whether two multimillionaires jerking around minimum-wage employees for laughs is a good look.

When she announced her first comedy special in 15 years, December 2018’s Relatable, which Netflix bought for $20m, it looked more like an exit strategy than a side hustle. Maybe it should have been obvious that she was ready to move on back in season 13, when she changed her theme song from Let’s Have a Little Fun Today to a Pink composition that includes the line, “been kinda bored lately”. She recently confirmed to the New York Times that she is unsure whether she will continue the show once her current contract ends in 2020. Let’s hope she has the vision to know when to stop.