If a group of miners choose to change consensus (e.g. raise the cap), they de facto hard fork and create a new coin.

The new coin could replace Bitcoin. But why would anyone leave the original chain/consensus ?

Miners could threaten to make the original chain unusable, multiplying reorgs and nuisance. The cost would be astronomical and only coordinated pools could, in theory, do this.

But if they do, the individual miners would instantly redirect their hashrate to unaffected pools. The attack would fail within minutes.

Institutions could choose to leave the original chain, but is it that much of a sell pressure ? Maxis would be thrilled by the redistribution. And institutions will have lost everything.

The miners work for the nodes, which are the bitcoin end users.

Run a node.