When Google co-founder Sergey Brin wanted to make a splash with a new piece of technology in 2012, he orchestrated an elaborate display that landed skydivers on the roof of Moscone West, with the dome of the Westfield San Francisco Centre in the background. The city’s urban landscape made the best possible backdrop for video-capturing Internet headgear that promised to change our lives.

Now, Google Glass is a footnote to tech history. And so, too, may be the big tech showcases that made San Francisco a mecca for Silicon Valley engineers and executives seeking to put their wares on display before the world. The Bay Area’s largest tech companies — Google, Apple and Facebook — are all moving their developer conferences out of the city and farther south.

While developer events like Google I/O, Facebook’s F8 and Apple’s Worldwide Developers Conference are targeted at a technical crowd, the companies also invite media from around the world and use keynote speeches to reveal new products and strategies. They also attract a host of events and parties thrown by other companies aiming to capitalize on the buzz and the crowds.

“This kind of trend moving from San Francisco is going to hurt,” said Rob Enderle with advisory services firm Enderle Group. “San Francisco was perceived as very trendy at one time. It just isn’t anymore.”

Google moved I/O, an event with about 7,000 attendees, to Mountain View last year. It will remain there this year. This year, Facebook followed suit, moving its F8 conference with 4,000 expected attendees to San Jose. And on Thursday, Apple announced that after a 14-year run in San Francisco, its developer conference would return to San Jose’s McEnery Convention Center.

Analysts said a number of factors could play into the moves. The Moscone Center is undergoing an expansion that will close Moscone North and South from April until August. (Moscone West, which Apple and Google have used for past events, will remain open.) Besides the limited space, construction could be a turnoff to businesses. Also, the high cost of staying in San Francisco and snarled traffic could be factors.

San Francisco’s loss has been a boon to other neighboring cities including San Jose. The McEnery Convention Center estimates that events like Apple’s can bring in $5 million to $7.5 million in direct spending .

“Any time we have any large group in San Jose, there is a very large economic impact from that,” said Karolyn Kirchgesler, CEO of Team San Jose, which aims to bring more tourism to the city.

In a news release Apple pointed to the close proximity of San Jose’s McEnery Convention Center to its headquarters in Cupertino. Roughly 25 percent of Apple’s Silicon Valley employees live in San Jose, making the commute much shorter for employees who plan on attending the event.

Facebook said it moved out of Fort Mason because it outgrew the space . Last year’s event drew more than 2,600 developers. This year, Facebook expects about 4,000 developers will attend. It too, is choosing San Jose’s convention center, which “could better meet demand from both local and international developers,” a Facebook spokeswoman said.

Google said it opted to bring its developer conference back to Mountain View because it wanted more freedom to create spaces that would best showcase its technology. Last year, the company was able to present its large Project Loon balloon at I/O, something that would not have been possible in a traditional enclosed convention space.

“We were able to create spaces for the appropriate size for whatever it was we were explaining,” said Lauren Dales, a product marketing manager for Google I/O.

Twitch, Amazon’s video-game-watching site, also moved its convention away from San Francisco in 2016 and hasn’t returned. This year’s is in Long Beach. The amenities there “resonate with our community,” said Krystal Herring, director of TwitchCon. One of those benefits is “excellent” hotel rates, she said.

Cities outside of San Francisco said they were thrilled to have an influx of developers coming this summer — with some banking on the bragging rights that come with being the home to the companies’ headquarters, too.

“Part of the reason the city of Mountain View is known worldwide has to do with the businesses we keep,” said Alex Andrade, the city’s economic development manager. “Absolutely it adds to our brand. Our brand has gone from local-regional to now incredibly global in that respect.”

San Francisco said that it hasn’t seen an impact from the loss of the developer conferences. The estimated direct spending from conventions and meetings in San Francisco is $754 million for 2016 and it doesn’t show signs of slowing down, according to San Francisco Travel Association.

John Reyes, the association’s executive vice president and chief sales officer, says there already are inquiries from parties interested in the dates that Apple will no longer be using at Moscone.

“There was a big fight to keep (Apple) here,” Reyes said. “We take every booking or event in Moscone very seriously.”

Moscone may face more competition for Apple’s business in the future: Apple’s new Cupertino campus, set to open this year, will feature a large theater space for unveiling its latest technology.

To be sure, San Francisco is still home to other large tech conferences, including Salesforce’s annual event Dreamforce and this week’s RSA conference, where people discuss the latest in cybersecurity.

Darin Andersen, who flew in from San Diego to attend RSA, said coming to conferences in San Francisco is always special.

“It’s more than the experience of the conference, but it’s also the context in which it happens,” he said. “It would be a different experience” outside the city.

But for employees coming from the South Bay, a conference in their area is much preferred.

“I had to wake up at 4 a.m.,” said Erika Borquist, a support engineer with Rayne Technology Solutions, a company based in Monterey.

It took Borquist and her colleague about three hours to get to San Francisco on Thursday morning. While there are certain perks to being in the city — such as the food, she said — dealing with parking and traffic is a hassle she would happily avoid.

Staff writer Benny Evangelista contributed to this report.

Wendy Lee and Trisha Thadani are San Francisco Chronicle staff writers. Emails: wlee@sfchronicle.com, tthadani@sfchronicle.com Twitter: @thewendylee @trishathadani