If 99% of all PoS coins shut down and went home the only thing that would happen is people would stop losing money buying the pump-and-dump shitcoin-of-the-day from the Altcoin Announcments forum.

The greatly increased scam potential alone that has resulted in almost all new shitcoins being PoS coins should be enough to scare away most careful investors. But if you want to bet on trying to find that 1% of PoS coins that are not outright scams and on PoS being sound enough to actually work despite warnings from nearly all competent analysts, go right ahead. And I really do mean this. Being willing to go up against the prevailing wisdom of experts is a great thing and important to progress. Just know that the odds are very much against you.