People are morally complex than that. Lots of people have no idea what they're invested in and many people work for companies like Meta and Amazon because they have no other work options.
And FAANGs have an entire industry around getting into. They are not and never were the only option. They're notoriously the more difficult option, and during the last 15-20 years when this was all being built, software had some of the best career prospects. No one was forced to work there. They had to go out of their way to do it, and a lot of them specifically practiced for it. They knew exactly what they were doing.
Even if it were their only prospect, just like if a theft ring were someone's "only prospect" (it's also not), the correct answer is still to stop them.
Or like the gambling thing: it was already illegal. All they had to do was not make the world worse. The saga that led to its legalization started with a voter referendum. Then other states jumped on the idea and took it further. No one needs hindsight to realize universities pushing their students to gamble on sports is evil. There's no "that's how it's always been" to excuse themselves; they thought of a new way to exploit young people and did it.
In any case, even if you grant them being merely indifferent instead of malicious, that still earns them indifference toward whatever troubles fixing the damage they're still right now bringing might cause them.