I completely agree. Not the point I was going for, but it's a fair one to make. I've long thought that all of these "benefits" are a cloaked way of Silicon Valley companies to exploit their employees under the guise of generosity. Not to mention the complete elimination of work-life balance.
It's true, except I don't think they're generally expecting the perks to cause you to work overtime. It's more that if you're going to make people work crazy hours, and you don't want the high turnover that comes with burnout, you take care of the needs they aren't going to have time to take care of themselves because they're working all the time. It's not the mechanism by which companies exploit people, they do that by making unreasonable demands, it's the mechanism by which companies that are going to exploit people keep them from saying "fuck this" and walking.
A year or so is the average stint everywhere, because there are a lot of options and for most of them the only real requirement is knowing the tools, so changing jobs is easy. If you're Google or Amazon you want to keep the people whose primary qualification is knowing information retrieval, or machine learning, or..., you don't care about people whose primary qualification is being able to make python sing and dance because the guys who can make python sing and dance can make python sing and dance anywhere, and are liable to leave because they want to play with a new toy, or have an offer near their favorite pizza place, or...
Few things make me happier in the work realm than not having a company cell phone. Everyone knows that when I leave, good luck, see you tomorrow.