The only reason Meta is able to persist is because relatively well off software engineers keep working there. Vote with your feet Meta employees.
Plus, if a principled and ethical engineer leaves the company, I assure you there is a large backlog of very eager replacements. Personally, Id rather see effective dissent from within the org.
There's really no such thing, simply because of that large backlog of eager replacements
From the company's perspective they will happily fire you if you dissent and replace you if they have to