Some people work a short period to get a taste of the tech stack and pace of a FAANG while other people post to HN about upcoming interviews at Meta and how they may hate the company's morality but want that big fat comp package. Everyone has their own reasons for taking a particular job and sometimes that calculation needs include the cost of associating your work history with the brand of the company you are working for, but if you think that what you are doing and the impact it has on the rest of the world is important then that warm and fuzzy feeling is a part of the compensation you are maximizing. In the long run no one will care, so anyone who is not maximizing compensation is probably a fool.
Big companies are actually like a conglomeration of small companies under an umbrella company. The culture is 20% upper management, 80% local management, and so your experience will differ greatly from department to department.
Bad managers exist in most companies. They can and do target people for personal reasons, and usually the targeted person doesn't have the protection or political clout to defend themselves, so they're killed off and life goes on.
I had a similar experience at Canonical of all places, which was a real drag because they were one of the few fully remote companies at the time, and I like the company.
Not everyone has the opportunities you have had. Some people actually have to struggle to climb for X reasons, and make tradeoffs to enable them to survive / grow.
Some people actually need money and can't just ignore wads of cash being thrown at them for the first time in their lives.
You're fighting ignorance with more ignorance.