With PoW there's a cost associated with producing a coin with mining equipment and electricity so miners won't sell their coins any cheaper than that which creates a floor price. With PoS there is no cost of production, you just have to own and hold coins which also means that everybody can stake their coins.
Another significant difference is that newly generated PoS coins are going to people who are already holding the coins as a reward. That is generally not true for PoW. And more coins mean inflation so in essence PoS coins are rewarding stakers with free coins at the cost of inflation. Personally it doesn't make sense to me why anyone would invest into PoS coins especially considering the average lifespan of coins and how rapidly things change in crypto - but that's jut me.
I have heard that floor price argument quite alot, and most of the time people get it wrong (I am not saying you do, I dont know).
Economically the costs at which the coins were produced are irrelevant. The only thing that matters are the costs to reproduce the same coins in the moment of selling. Thats the first thing so many people fail to understand when asking what the mining costs of a coin were. I admit there is a psychological barrier to sell at a loss once you have mined which might create a temporary floor, but not for long. Its not like we havent seen miners sell at a loss before.
So what matters are the current production costs , not former costs, which means the current hashrate. For me mining a coin is just another form of demand. I can either buy a coin directly or chose to mine it. In case of POS coins, mining is not an option, so all demand is manifesting as demand on exchanges. I really cant see why the possibility of mining a coin - if you accept what I just wrote - does add any floor. POW coins can just die as POS coins can die.
I also really dont see the problem that staked coins go to those that already have coins, unless of course we are talking about one of those 250%+ coins, but we will all agree that those are more for fun/gambling/ripping off people and irrelevant in the long run.
The average lifepsan of a POS coin is pretty short, but the same is true for many POW coins. There are quite a few POS coins in the top 30. That the top ten is heavily dominated by POW coins might have something to do with the first-mover advantage (its not like the second doesnt have an advantage over the third and so on, just smaller). If I am not mistaken the top ten is not so much dominated buy POW, but by older coins - that all used to be POW coins. Feel free to correct me here as I am not entirely sure here.
