I mentioned this before, with Bitcoin POW a small percentage of Bitcoin holders are securing the network. Most people have Bitcoin in a wallet and that's it. They are not participating in the network. So your example of 10-12% of ETH securing the network is no different that the current situation with POW Bitcoin or POW Ethereum. There are over 300,000 validators.
But who is securing the price?
What if If 88% of the coin holders sell Ethereum 2.0 and buy Ethereum POW.
What if 88% sell Bitcoin or Cardano? You're just grabbing at hypotheticals, and have a cleared anti-Ethereum agenda. Keep things positive and try to avoid negative talk. Remember people are invested in this. You enjoy seeing people get hurt financially?!