Google once played up the nerdy antics of its founders, but now the company’s leaders are almost unidentifiable ciphers. Larry Page, who runs Alphabet, Google’s parent company, has become a recluse, and even Sundar Pichai, Google’s achingly pleasant chief, declined to appear at last week’s hearings.

Jeff Bezos, Amazon’s chief and the world’s wealthiest man, has been experimenting with a more daring fashion sense, but his leadership style has always been marked by patience and deliberate expansion — just the sort of boring, operator’s sensibility now in vogue.

Oh, and I almost forgot about Satya Nadella, Microsoft’s C.E.O. In my defense, everyone forgets about Mr. Nadella.

It’s no mystery why tech leaders are turning inward. “Tech is now such a huge and dominant industry,” said Joshua Reeves, the proudly boring founder and chief executive of Gusto, a start-up that makes human resources software. “The fly-by-the-seat-of-your-pants mind-set is just not viable when you have a trillion-dollar market capitalization or if you have more influence than many governments around the world.”

Mr. Reeves pointed out that it’s not just the big companies whose chief executives are going beige. Some of the most successful start-ups — from Lyft to Airbnb to Stripe to Slack to Pinterest — are run by understated un-visionaries, people who aim for functional competence over hypey salesmanship. (What hasn’t changed is gender; boring or no, just about everyone who runs a tech company is still a man.)

“A start-up that has five million people using it — that’s small for Silicon Valley, but it’s a tremendous number of people, and so even they have a large amount of responsibility in the world,” Mr. Reeves said.