> From centralized exchanges, to centralized mining cartels, what does something like Bitcoin have left to offer?
I'd say you're being overdramatic here. Mining is still decentralised and if there are any mining cartels, they haven't abused their position yet. It's still possible to buy, sell and spend Bitcoin peer to peer as well.
I think part of the reason Segwit2x failed is that, ultimately, mining wasn't as centralized as everyone assumed. Its proponents had the backing of the major mining pools who controlled the vast majority of the mining power - or so they thought - but it turned out enough of the actual miners had views too and were happy to switch pools to express them that it suddenly looked a lot more precarious than expected.
I'd say you're being overdramatic here. Mining is still decentralised and if there are any mining cartels, they haven't abused their position yet. It's still possible to buy, sell and spend Bitcoin peer to peer as well.