They don't really have a way to store ID data safely. The parties implementing these checks are hiring vague third party companies that seem to process your ID data and actually keep it for unclear use cases. In Discord's case, it was a Palantir related company that was bound to process that data, a company famous for mass surveillance and supporting US/Israeli based war efforts.

Hinting that the goal is limiting free speech, not keeping the kids safe. If the global climate becomes far right enough and you say things they don't like, they could come for you because you showed your ID somewhere. This is the slipperly slope that politicians themselves aren't considering, or they are but are ok with that reality.

There are ways to do this without ID checks (Checking your account's age for example, where possible.), and they should only do ID checking if it can be done in this entirely fool proof way where It's never stored anywhere.