(opinions my own) - I actually do work for $FAANG and can confirm this statement. Mountains of tech debt, 20+ year old tech running most of the stack, most tooling written in dynamic interpreted languages, and above all else every single engineer is expected to be part of on-call rotations, even if your role is not related to infrastructure or operations whatsoever. Even if you don't touch the service(s) your team maintains because you're in a FEE role.
The SDE role at $FAANG I work at is essentially glorified tech support, which makes the leetcode interviewing process so much more ridiculous than it would be by default if you were actually writing code and solving meaningful problems most of the time.