PoW gives bitcoin an unforgeable cost. This means that for bitcoins to be created an earned by miners they have to spend electricity. So there is a real cost to create and earn bitcoin that cannot be faked. Current currencies don't have a cost, they can be created at the press of a button from thin air. Gold also has a cost, it has to be mined, work, time, machines, can't be created from nothing. Now POS to create you need 32 eth that can be faked, if you can print money from nothing you can buy 32 with no cost. For Bitcoin you can also buy with money but we are talking about the production, you can buy bitcoin miners with fake money but you still need to spend electricity, a lot of it. Same with gold you still have to put the work. So to mine bitcoin or gold you have to keep putting real energy/work, for POS you buy 32 eth and it's done, you keep earning without any work. This bitcoin and gold costs also forces the miners to sell to pay for operarion costs, that makes bitcoin more distributed among everyone. In POS you don't have costs so you don't have to sell, so the richer get richer and power concentrates in the rich, in POS the interest is paid by the users, so users get less eth and nodes get more without the need to sell.
A ton has been written on the topic though. But starting here, do these ideas make sense?