I've contemplated the idea of a coin that has a single wallet per person (sybil-proof identities must be implemented), these wallets have a max-limit of 1 billion coins, and coins are minted/staked and applied randomly to the lowest 5%, maybe it'd have a use-it-or-lose-it thing built in as well, where if you just sit on your coins and never have any transactions occur it just assumes you might be a "dead" account and recycles a percentage of your coins for "unuse", and that percentage goes up the longer you are without any transactions until it just redistributes your entire wallet...

Example would be if you had 1 US bank account sitting on a billion, never used it, so the govt is like, well you're not using that so we'll give it to someone else lol.

I personally am against billionaires existing. So, capping a coin at 1 billion or 999 million, makes sense to me - but only if there can ever be only 1 wallet per person. There could maybe be sub-wallets, but these are more like drawers in a dresser where the dresser is the wallet, and the drawers are compartments. Maybe a compartment in the wallet is a joint compartment that you share with a spouse, child, or a business/DAO or some other form of trust...

There's a lot of things possible, that could happen... but I think PoW still makes bad sense, because we do have a global warming issue that is starting to pick up in terms of severity.