Dynamic Users are neat and probably very useful for a tmpnb
style situation. However, for regular use they have the following
problems:
1. Can't set ProtectHome=no, so you can never apt install or
similar from inside admin accounts.
2. Dynamic uid / gid makes it hard to write sudo rules. We want
admin users to have sudo.
3. Persistent uids / gids are very useful for ad-hoc ACLs between
users. gid sharing isn't the most flexible sharing mechanism,
but it is well known & quite useful.
4. /etc/skel is pretty useful!