Bitcoin

Today, a majority of BTC is traded and custodied on CEXs. With the advent of ETFs, in the long term BTC will effectively be controlled by a few regulated CEXs. Might as well cancel PoW and go PoA - it'll actually be more decentralized than 2 mining pools & a handful of profit-maxi centralized mining corporations.

PoW (or PoS) are useful for forming a status quo. But beyond that certain point, due to economies/entrenchment of scale & lack of redistributive mechanisms, they will likely only centralize things further. When the time comes, replacing them with a better mechanism will be essential for minimizing centralization.

BTC is stuck with PoW because mining interests got too powerful. Ethereum’s PoW is the leading protocols increasingly openly copying the big tech playbook of acquisitions, lobbying, and copying