For me it comes down to the simple fact that PoS rewards those who already hold the most wealth--they no longer even need to work for it.
It rewards everyone who participates in proportion to their holdings. Everyone gets 10%.
They do need to work for it, though: they need to validate transactions. Only people who operate full mining nodes get the dividend. Coins held in cold storage get nothing.
I think this creates more opportunities for rent-seeking and less impetus for innovation.
I don't see why you think that.
See the point you make in bold. rent-seeking is how you get income without working. (They don't work the computer program does the work)
Bitcoin favours efficiency. Our current system favours debt and consumption.
PoW is not efficient; that's the point. It favours a never-ending arms race of escalating consumption of computing resources, presided over by an elite with the capital to buy it and the expertise to run it.
It is actually the other way around. PoS is more energy efficient at maintaining a cryptocurrency. It is not efficient at allocating capital in the economy as a whole. Capital is used to fulfill need, currency is the conduit. If you can fulfill need by not working and just holding currency then capital from the economy will accumulate in hoards of revenue generating currency.
And those who need to use currency will do what those who have hoards of it what.
Competition in PoW insurers those who make the currency have to spend it into the economy.