I don't agree with the following statement you made;

eventually we'll need central authorities just to hold and process all the data because individuals will lack the required resources

After all Bitcoins are rewarded to the miners there will be still some interest in processing transaction fees by validating transactions. At that time ASICS machines may go out of the picture completely.
Most of the alt coins will be doomed. Also every country will regulate BTC enough to rip tax benefits from the citizens as centralizing it is not logically possible. Let's see what future brings for this space. Good luck all who are HODLing. Cheers!!!