

You do realise you can easily restrict who can run what applications (or terminal commands) by using guid? So you can easily restrict a child account being able to execute applications or games already? And you know what, this method does not rely on application developer implementing any kind of age gatekeeping using DOB field… Its generic to all distributions even ones that don’t use systemd. This is why this change is dumb and not needed.
You can even use it to restrict access to terminal commands such as curl so children cannot download something they shouldn’t…

Right so mixed content steam already has parental controls specifically with an allow list
GOG provides individual installers, so you can control its access with
guidContent players pretty much all have child accounts
Even locally hosted ones, like Plex already have parental controls built-in (mostly via allow lists)
What other kinds of mixed content applications are there that already do not have some kind of parental controls implemented which are likely to actually make use of this?
I am honestly struggling to find specific examples of the types of applications which have mixed content, don’t have parental controls or at least allow lists built in and are likely to actually implement this change. Again you are relying on developers to actually make use of this field, and outside of corporate applications (which imo are already likely to have some kind of content controls), I am struggling here to see why an indie developer would bother?