The POW system puts everyone on an equal footing as far as Bitcoin is concerned. Sure, Bitcoin isn't going to fix people being mean and unfair to each other. But Bitcoin allows the people who use it to hold their wealth in a way that can't ever be debased or stolen.
Exactly. In PoS, you have to stake your coins since else you get diluted by others who stake.
In PoW, you can actually use your bitcoin to buy stuff.