when/if bitcoin becomes mainstream the majority of bitcoin users will use and rely on online wallets and exchanges, if these centralized companies collude together with big mining companies they will have the biggest blockchain and people won't even have the choice to change blockchain if they want to keep their money.
I think the only real way the consensus mechanism would work as it should is if the blockchain is forked in a way that anyone can mine and earn bitc, maybe by putting some sort of limit on processing power/node, decentralized mining is the only thing that will preserve integrity of the protocol IMO
I really wonder if there's going to be a way to get away from that outcome. Convenience and preserving their funds is more important to most people than decentralisation even when that's the core principle.
Circle/ Coinbase etc are already engaged on a slow creep towards being cornerstones of a future system. The miners are a much more random element but many are just out to make the most money.
By the time it become clear that decentralised mining is really necessary to keep the flame alive, the block reward might not be worth it any more.
It's quite possible the whole thing will closely follow the trajectory of the internet. What began as the wild west slowly became another facet of everyday life with a side order of extra freedom if you could be bothered.
