I think ethereum is one of the best altcoins at the moment and in my opinion ethereum really deserves to be included in the POS category with a fairly limited supply and of course has very high potential and popularity in the crypto market, and until now there has not been a single altcoin that can replace it. ethereum's position in the top 2 CMC.
I completely agree with you that Ethereum is the leading and most influential altcoin in the cryptocurrencies market today and it fall in Proof of stake (POS), however its maximum supply is unlimited while supply bin circulation is 120,128,511 which seems relatively low. I think despite the unlimited supply, its extensive real life use case such as, smart contracts, decentralized applications (dApps) and decentralized finance (DEFI) solidify its position as most popular and valuable altcoin.