I think there's a conflict of interest issue here that would prevent such a move even if it would be worth it - the miners clearly have an incentive to keep the current PoW mechanism, as without it they're left holding a bunch of expensive useless tech. And without the miners willing to go along with a move from PoW to PoS, at best you're going to get a split between the PoW and PoS chains rather than a clean shift from one to the other and just create a mess, which isn't ideal for anyone.
All that matters is the market's valuation of the currency: it would be irrational for miners to do anything except expand until their costs nearly match the reward.
I think the answer to what you actually said is; miners don't control consensus on the network - it's not up to them, it's up to fullnodes/users who can change the ruleset whenever they want.
And I agree to a point, but miners are the ones that effectively run the network, and there aren't actually all that "many" of them. Without the existing miners willing to contribute the existing network would fall apart. PoS is an interesting situation because it technically makes the miners unnecessary, but obviously the miners are going to say "no" and just keep going with the existing Bitcoin. It would just create another Bitcoin Cash situation effectively, which is a lot less appealing than if everybody switched to PoS and left nobody using the old version.
The reason you haven't seen this in the global cryptocurrency industry is because of network effects and adoption curves. Most programmers would probably agree that C++ is archaic and that the software industry has moved on to newer languages like Rust, Go, Kotlin, ES6, etc. Why then do Microsoft, Amazon, Apple, Google, etc. all rely on large quantities of C++ code? Because they were founded in the last millennia, when C++ was basically the only alternative for what they were trying to do, and have deeply enmeshed ecosystems and value chains that are all dependent on their existing C++ codebase. Throw it out and you throw out the $5T+ in value they've built. They couldn't have built that up without the 20 year head start they have, but if you're founding a tech company now, you're pretty dumb to use C++.
Similarly, Bitcoin has built a whole ecosystem of miners, speculators, traders, exchanges, payment systems, wallets, etc. Throw proof-of-work out and you throw all that out, and along with it your advantage over Ethereum, Cardano, Stellar, etc.
All us unreal engine using indie developers must be pretty dumb then. It’s true that programming in c# in unity is easier, but the end result of the c++ is a prettier game with more things happening at once at a higher frame rate. More grass, more characters, more animations, more AI nuance, more physics interactions, lower system requirements during a gpu shortage, etc