Even if the applications are just weird forms of entertainment, that's still demand that people are paying real-world money for, since they have to spend their real money to buy the ETH. Non-blockchain gaming is a fairly big industry and all the money people spend on in-game purchases doesn't have any more connection to the "real world," but is still valid for financial valuations of the gaming companies.

There are people (especially at EY) working on using Ethereum as infrastructure for things like B2B transactions, but that's still in early stages. And here's a recent piece by Vitalik on non-financial applications of blockchains: https://vitalik.ca/general/2022/06/12/nonfin.html