PoS works by people staking their coin. . no intense computation needing superior hardware
it creates no value. there is no 'cost' in mining. people can put their stake in. and later take it out. no loss

this makes altcoins with PoS have no underlying value in its coin creation. thus reliant on value from the features of what that coin can do/be used for after the creation to keep the coin active/alive.

bitcoin has a real cost of creation via the mining hardware. much like golds underlying cost is in gold mining costs.

because it costs $10's of thousands in electric/hardware to make just one bitcoin. (more precisely hundreds of thousands per 6.25 reward) that gives bitcoin a baseline value. which no one wants to sell below. thus giving bitcoin a good actual store of value.
yes there is the vapour/speculative/bubble premium ontop thats volatile. but thats the same with gold

golds underlying cost value is like $1k and the rest of the 'premium' that makes up the combined 'spot' price is the speculative supply/demand, hype

the only reason people want PoS is because the fantasy of profit for nothing. or no-loss profit. but the thing about PoS is if a coin was successful and everyone was using it. eventually the slicing up of the reward being split between everyone involved would leave everyone with nothing. thus majority lose interest

PoS is just a fantasy of getting rich for free. whereby it only really works by pump and dumping the coin to keep it viable and entertaining enough to avoid just turning into a zero utility coin.

because the amount of blocks are limited a viable coin would end up with people having to syndicate their stake into a group of people. much like how bitcoin mines in groups. thus again making it no different and having the same competition. but with an PoS altcoin its a fight to the bottom rather than with bitcoin which is a fight to the top

bitcoins mining method is more secure then PoS and the more hardware competition to mine = stronger hashing which cant be undone as cheap. bitcoins security grows.  cost grow. meaning base value grows.

altcoin PoS security does not grow. no matter how much is staked. and if it got popular. there would end up being more people wishing to break an altcoin for quick riches rather than stick to the rule. PoS only survives by having a small userbase of stakers and just enough enticement and fantasy to keep it active.

basically the more that use bitcoin the stronger it gets.. the more that use PoS altcoins the weaker it gets. but it requires enough peters to pay pauls so that the early stakers can leave, but have enough later stakers to keep the fantasy alive.

PoS is not a thing you want to use for something as big as bitcoin.