The crux of the problem is that gmail is, for billions of people, both their primary email account, which is superbly central to many things that we do in 2022, and the way in which we get authenticated and essentially "manage" our online identity.

These two things would ideally stay separate. Of course, an expert in Computer Science would certainly have his/her own tld domain with email, and maybe use gmail only for proper email work, right?

Well... Not so sure about that. I'm a tech person myself, and my gmail is my online identity. I would suffer the same fate if I were to go through the same issue as OP's mother.

Perhaps there's space here for a startup, or a service, that allows you to fix this. Something that would make regulatory bodies not too unhappy about it.