I only have experience at one FAANG (and the culture varies from one to the next, so not knowing which one you're at, it's hard to say).

Couple of things about them that can differ from other firms:

1) The one I was at heavily rewarded self-motivation. If no work is getting done, the work for the engineer to do is identify why that is and either overcome the obstacle or build support and service tooling so that when the obstacle is removed, the team is ready to hit the ground at full speed. Think like water; if you hit a wall, don't freeze... flow around or over it, and fill the space you occupy.

2) Software engineering at the FAANGs differs from other places (especially startups) because, to be blunt, there are stakes. The only thing startups are out if they fail is money. FAANGs make software relied upon by billions of people, trade hundreds of millions to billions of dollars, and have sweeping cultural (and in some cases physical) impact. I don't know what project you're on, but some projects cannot allow for error in software development; it translates to lost dollars, lost goodwill, or possibly lost lives. I've never seen practice at a FAANG that rises quite to the level of industrial / physical infrastructure or aerospace engineering for quality control, but it gets up there. To that end, the processes are wildly different from ones a person may be accustom to at a smaller company, because there are systems in place designed to minimize the risk of engineer error. Sometimes, that means the engineer can't make progress until they learn enough to know why the system is stopping them, and that is by design; it's how the company encodes decades of hard-learned failure lessons into the process itself. It's more taxing than a startup's process, but that's because startups tend to create, in contrast, teetering edifices of fragility (consider Twitter's early years when they unexpectedly got popular; Facebook, Google, and Amazon can't afford to just have a service not work because of the failure mode "people actually want to use it"). And sometimes, progress at FAANGs gets slowed because unlike smaller companies, they have to consider whether what they're doing is good for society in some sense (either from a moral stance or, far more often, the practical stance of "We need an internationally-scoped legal review on this feature so we don't get sued out of a tenth of a quarter's worth of profits").

3) Some FAANGs are much better at software than management. They assume individual engineers will know when things aren't going well for them and will self-correct. To my mind, that's an error (not a lot of engineers I've met are comfortable with emotional self-direction, and it's certainly not taught in software engineering curricula), but it's what I've observed. It may be helpful to talk over your concerns with a trusted coworker (ideally on another team, to minimize the odds of any promotion jealousies creeping in) and see if they experienced something similar and what they did about it. In my experience, most engineers at the FAANGs went through a period of feeling like this wasn't for them at some point.

4) There is absolutely such a thing as a sucky dead-end project in FAANGs. My first project was one. I didn't do anything like find my footing until I got off of it. It eventually disintegrated under the weight of its own bad engineering decisions, but I lacked the perspective at the time to realize I was standing on a sinking ship. It was a ship that made an awful lot of money though, so the company was extremely willing to throw careers at it to keep it afloat, if the engineers doing the bailing were willing to hold the buckets.

All of that having been said... Even after I found projects that resonated with me and I could make real contributions to, I left because I felt like my career was stalling out working on projects at a glacial pace with mixed chance of success, even knowing why we did it that way. If the work isn't fulfilling, and if you can't see a clear path from the value of the product to benefits for real people... Maybe it's not worth you're time.