What would Bitcoin community do if Blackrock create a hardfork?

So i was thinking the whole value of bitcoin comes from its community and people like me who believe in their freedom and decentralization. Since bitcoin came on live there have been few hard forks.after blackrock and other major financial institutions are coming to the field, i was wondering the fact that they control lots of hash power of the netwrok they could easily do any changes they want and make it so. Maybe they change the 21M cap or something. If such thing would happen, what can we do in order to continue the path and not letting them get this out of the hand of the people and into their own?