I totally see why employers love that.
Additionally, FAANG and startup tech offices often serve as more than an office - they tend to have a lot of shared amenities that are just not practical to have at home. I don't use a 3D printer often enough to own one, but there is one in the office. Gym? Office, and it has more than a pull-up bar. Post office? Office. Inbound packages? Post office. In the office. Grocery shopping? Happens much less often if you eat out. In the office. Why would I want to eat out of my own fridge and pantry (and have to prepare the food myself) when I can grab tasty food prepared by people who actually know what they're doing?
The benefit isn't just that the stuff is free; the benefit is that it's all right there. It's an incredible time saver.
This is going to be a huge benefits cut for tech employees, and a massive cost-cutting measure for tech employers.
If the office is just an office with no amenities, and you have a sucky commute, then I can see why WfH would be attractive.