Miners can’t increase the supply. It would be if nodes/validators are highly centralized.

The economic majority would be who determined the rules, even if 95% of the miners switched to a shitcoin fork with increased supply. If none of the nodes did, they’d have zero market to sell to, and all those validators would now have a shitcoin to dump on the market for more BTC. The price would plummet in their fork, made even worse because their blocks are coming in faster, while BTC just sits and waits with a billion person network to sell to.

Mining centralization is a problem, but it isn’t because they can just randomly change the consensus rules.