Much more interesting is why these two companies were able to wield this much power in the first place, and why are they using it to censor this kind of content specifically?

You can't understand anything about the situation without replacing it in the context of the far right reactionary wave hitting our societies. Similarly, simply preventing these two companies of their power would be a temporary solution at best. There is a political will -and enough support for it- to push the puritan agenda.

If you truly care about fighting censorship, you should recognize where it actually comes from and fight the source.