Google and Facebook I don't think are cheap for developers. I can speak firsthand for my past Google experience. You have to note that the company has like 200k employees and there needs to be some controls and not all of the company are engineers.
Hardware -> for the vast majority of stuff, you can build with blaze (think bazel) on a build cluster and cache, so local CPU is not as important. Nevertheless, you can easily order other stuff should you need to. Sure, if you go beyond the standard issue, your cost center will be charged and your manager gets an email. I don't think any decent manager would block you. If they do, change teams. Some powerful hardware that needs approval is blanket whitelisted for certain orgs that recognize such need.
Trips -> Google has this interesting model you have a soft cap for trips and if you don't hit the cap, you pocket half of the trips credit in your account which you can choose to spend later when you are overcap or you want to get something slightly nicer the next time. Also, they have clear and sane policies on mixing personal and corporate travel. I encourage everyone to learn about and deploy things like that in their companies. The caps are usually not unreasonable, but if you do hit them, it is again an email to your management chain, not some big deal. Never seen it blocked. If your request is reasonable and your manager is shrugging about this stuff, that should reflect on them being cheap not the company policy.
They eventually became so cheap they blanket paused refreshing developer laptops...
Personally I think the other half of the problem, Big Tech paying so much might be solving itself right now, excepting really only the very very top.
When Silicon Valley was cheap enough to live in that people could casually start a company in their garage... Then people didn't have to relentlessly optimize for short term comp.
Today you have to work at FANG to afford a garage in the Bay area.