The OP's fundamental frustration (I think, oversimplifying) is that they feel no incentive or no motivation to "do better" or take on the kind of things you suggest. They do not believe it will be rewarding to them, and so what's the point? So, I don't think it's a problem of, they never considered these options before... it's more just, why bother?
Few observations for the OP:
- These are potentially signs of depression in general, that nothing seems worthwhile and you don't want to engage with any activities. Are things outside of work still engaging? Do you put your energy into other hobbies? Or does everything feel tinged with this same flavor of generalized discontent and oh-whats-the-point?
- Setting aside depression as a factor (which OP should seek diagnosis + treatment for, if relevant), in general this is also a self-fulfilling prophecy. By believing that your work has no meaning, that just being barely-better than the rest of the slow/lazy team is good enough, OP will make this into their reality. So in a sense, it's not an objective observation about FANG work-life, and more of a subjective decision to shape OP's reality into this mode.
- OP could be doing better work as you suggest (notice I said better, not more), improving their tech skills, adding impactful examples to their portfolio/resume, empowering their future career, but they're choosing not to. It's not as if the manager has actually blocked OP from learning or working on interesting things. And even if the team is a strategically unimportant team with no long-term career prospects, OP would still be hurting their career by not actually using this time more effectively, to add to their own portfolio of work or body of knowledge... So what if they won't get recognized or promoted for it on their current team, OP will still need to have something to talk about in future interviews or future promotion cycles on other teams. If someone asks OP, "what did you work on from 2019-2020, what significant value did you deliver, what did you learn, what skills did you gain?", what's OP's answer going to be?
- Speaking of promotions... it may feel to the OP that "coasting" along is going okay for now (i.e. no complaints from the manager), but I doubt they are at a career stage that they can really "coast" infinitely/indefinitely. In 2-3 years (or maybe sooner), someone will ask, "hey what has this person really done, that's meaningful or impactful? how critical are they to the team? feels like they're just coasting, right?". Even if OP isn't PIP'ed, they would still be extremely unlikely to earn any promotions, simply because, what is there to justify it? What next-level work have they done, if all they are doing is coasting? So, this is a fleeting/temporary situation, that OP is fooling themselves into thinking coasting like this is sustainable (because short-term, it is).