Short answer is they can’t. Nor can any company, not just social networks. The solution is balancing the power and ownership in society through redistribution, unions, or other ways. It’s harder to bribe the thousands of employees and shareholders of a company (if they have same votes).
I'm sorry, but when you say "redistribution" I hear "communism", which is always totalitarian. This would prevent the non-harmonious social network from existing in the first place. Even if a company is owned by it's employees - it is the case with Meta, btw, they might still vote for the highest profit, which in some circumstances equals not being shutdown by the totalitarian head of state.
I do agree with having checks and balances. One of the pillars, missing here, is having a legislature which is not too busy getting rich to exercise its role in society.
