I'm not quite sure where the GP got stressful, but it is soul-sucking if you expect your work to be interesting, impactful, and creative, which doesn't really happen apart from a few core or research teams. There is a ton of piping and rewriting of frameworks going on all the time, even when it need not be extremely useful. This is the main reason I found it thoroughly drab—even though it is likely that the lines of code I wrote there are likely to touch many orders of magnitude more people than anything else I ever work on for the rest of my life.
I guess that's just how it goes, though.
A number of people (myself included) seek to align work and passion all in one, which is fine, except it's certainly not the only (or, indeed, even close to "best") way to live and work. I've been lucky because my passion is in a field that now actually has applications in both theory and practice, after 50-or-so years of lying in relative academic obscurity.
The point is: if you care primarily about things that aren't your work (and this is true for literally 99.9% of people in the world, and is probably much healthier than the alternative) then FAANG is phenomenal in every possible way. The perks, compensation, and freedom to do pretty much anything are incredible. Quant (which nets around the same, if not slightly more profit) certainly does not fall in this category, due to its insane hours, and most other jobs with sane hours and good work-life balance don't pay nearly (read: really even close to) as much, or aren't as secure, or have anywhere close to the perks. It really is about the best gig you can get, if you can swing it.
On the other hand, for the weird, obsessive .1% of people (e.g., me) who would be happy to work all day in their mother's basement so long as it's interesting work, then FAANG (or, at least, many teams within it) can feel almost beside the point. Which is also fine!
I guess the point is that it all depends on what you want out of work and out of, well, not-work!