One aspect is already implemented, you open your webcame and it uses an AI tool to figure out if you are of age.

This is obviously ineffective but I must admit it's a bit of a boon for privacy enthusiasts as you can pretty easily fake the webcam using a game engine. Presumably someone will make a purpose built tool.

As well, if you aren't going to subvert it, and are willing to tie your identity to the discord account, it is still better than submitting government IDs.