Proof of work was the first of the consensus algorithms to be used with blockchains because Satoshi (imo, probably Hal Finney) likely didn't know about Proof of Stake at the time. By the time it was being discussed, Satoshi was already becoming less active in the community.
The claim PoS is not the best store of value is asinine. PoW in BTC has consolidated around a cabal of a handful of miners and the power usage is of course a well-known sounding bell for PoW apologists everywhere.
The truth is PoW was the best they had at the dawn of blockchain, then technology improved. It's really this simple and I'm baffled when people get religious about consensus algorithms. It's as if people would say we need to keep using bubblesort instead of quicksort because bubblesort was discovered first.