In terms of fairness of coin distribution, 100% PoS < Ethereum < Bitcoin < Pure Linear Emission.
PoS effectively ends the distribution of new coins, with everybody able to stake to just preserve their share of the pie.
With both PoS and PoW, a holder loses share when the total coin supply increases. On Ethereum at least, this is less of a problem with staking than mining, because staking is less costly so there's a tenth as much issuance.
However, with sufficient usage, the ETH supply actually shrinks, because a portion of fee revenue is burned. This means non-staking holders actually increase their share.
You can see how that's going here: https://ultrasound.money/
You are not supposed to buy ETH as a way to speculate on its price.
ETH is a resource used to represent processing and storage power. You can think of it as "AWS credits" that you can buy and use to run programs.
The absolute price of ETH is of no interest. The only meaningful number that you should care about is "what is the gas price compared to the ETH price", as in, "how expensive is it to access decentralized computing".
Speculating on ETH value is an investment strategy that is completely separate for ETH utility. People interested in the latter shouldn't care about the former. Just as people using AWS shouldn't really care about AWS stock price.
Yet Ethereum had a premine of around 60M, roughly half of all existing coins today. Later emission seems negligible regarding fairness.