But the issues that contributed to the walkout at Google — the company’s controversial work with the Pentagon on artificial intelligence, its apparent willingness to build a censored search engine for China and above all its handling of sexual harassment accusations against senior managers — proved too large for any worker to confront alone, even if that worker made mid-six figures. They required a form of solidarity that would be recognizable to the most militant 20th-century labor organizers.

“The myth of Silicon Valley is that all the power you need is embodied in you as an individual — if you want more money, go somewhere else,” said Harley Shaiken, a labor expert at the University of California, Berkeley. “What they were saying here was that all the economic power they had as individuals wasn’t enough.”

And the consequences of that dawning realization, Mr. Shaiken and other labor experts said, could reverberate across the entire tech sector.

Tech executives have long maintained that unions are inefficient — the Intel co-founder Robert Noyce once described unions as an existential threat — and that skilled tech workers don’t need formal protections because employers can’t afford to alienate them. Many tech companies also promote themselves as inherently pro-worker because they are less hierarchical, and more democratically run, than old-economy businesses.

Google, for example, points to countless ways for workers to communicate with senior executives: Employees can raise a concern with the chief executive at a T.G.I.F. meeting that happens a few times each month. They can ask questions on an internal company platform before meetings, and management will respond to the ones that receive the most “up-votes.” Workers can even circulate petitions, and those that prove especially popular can earn their authors a sit-down with management.