su is the best. I mean, i should be using the admin (root) password for admin things, not the user password of user who is already logged in. And there needs to be a root service already running to make user have root previlages which is dumb imo. Sudo vulnerability could cause previlage escalation but if there is no root process managing this, then it can't leak the root access. Only kernel security issue(or other root processes) will leak root access if that was the case, which i think is better.