I think the way discords setup works is reasonable. It’s an on-device model that only submits the outcome of the scan to the platform. I hope they just improve that performance, rather than see this and back out of it entirely and require ID checks.
I think this is the correct way too. Some of the age verification systems that use digital ids (mDLs) do the same thing but people freak out about how they work because I think they misunderstand the tech. They system basically asks the mDL via an api call "is this user above the age of 18/21" and the app only responds with a yes or no. It doesn't pass the users fulls details over or anything like that.
As in, if I repeatedly ask for age verification to the same service, does it know:
1) the identity of the user making the request, and 2) whether repeated requests comes from the same user (even if they don't know who it is?)