Blockchain and Games: what am I missing?

I keep seeing people saying that NFTs and blockchain would be great for gaming, but for the life of me, I can't imagine why.

Players could buy and sell assets.

Couldn't they already do that within the game's existing licensing infrastructure? Even if the studio opens up games to 3rd party expansions and additions, wouldn't the studios want to keep all that revenue within the company via an app store approach, taking a small percentage of every transaction? They already handle licensing via logins, so letting people buy and sell assets within the same game world would be easier than implementing an untested blockchain solution that relies on external verifications. What would the business case be for NFTs or blockchain approach?

People could move assets between games/studios

How would that even work? Even if different games use the same game engine, the way they code and implement weapons and skins wouldn't necessarily be compatible or even make sense in different styles of games.

Considering that adding this to a game series would probably be $500k+ (manpower, coding, testing, fixing, roll out and support, etc.), a studio seems unlikely to add this, especially if it lets revenue out of their company.