Could Bitcoin switch to PoS like Ethereum? That would also cause Bitcoin’s price to fall.
Have you thought about why since the creation of ethereum and as a number one leading altcoin it has not done so greatly proportionate to the number of years it has existed. Simple, it due to its POS nature, and a switch by bitcoin from POW to POS (which I don't see it happening) would mean that bitcoin will lose its independent status and value to which other cryptocurrencies follow suit at every moves it makes and become like every other cryptocurrencies.