The first flaw of the metaverse, in my opinion, is that there are too many of them. There is not a single virtual place that hosts all the virtual identities and their avatars. Each project has it's own metaverse, with own coin, own avatar possibilities, own NFTs, a handfull of compatible blockchains etc.

So pretty hard to reach huge numbers of unique users hundred millions and up.

At least for local implementations like a school, some courses etc sound more plausible.

Use a certain address to login and use the same address to send them scholarship payments so you make sure he does not share the pk.