The fans still have a lot of power, even against oligarchs or corporate giants. Most owners are in it for ego or as part of their wider business interests and they don't want to be embarrassed. Cardiff fans forced Tan to give in about the shirt colours. It can be done.. The reason why fans appear powerless is most supporters turn a blind eye whilst there is success on the pitch and only protest after they start losing. This is sad, but not inevitable. Brighton is a progressive place and we're a club with a proud history of mobilising and standing together and a good knowledge of the difference between a good owner and a bad one. If someone rich owner promised us £500M of blood money for players I think more would stand up against this than at most clubs
I agree with you that, if it happened now, it would be met with protest. I personally think this would happen for any club of similar stature to us. However, if we became a global superpower and had a guaranteed place in the European Super League, the hardcore fanbase is so small in comparison to the global appeal, that our voices wouldn't matter.
A more pertinent example perhaps would be Manchester United and the formation of FC United of Manchester. The dissatisfied fans couldn't fight a beast that large so said screw it, and started fresh in the image that they thought best represented why they supported Manure in the first place.