Well I don't demand sth. like user accounts. That was just a side aspect of the discussion having the possibility to revert/log changes. But generally it depends on your environment. If you have a lots of devices and admins you want to have user management and logging like any Cisco or Juniper router has. If you implement user accounts then it would make sense to have ACL as well implemented (IMO). E. g. for radius you could use ACL in connection with a firewall or you could use it for samba/nfs.
There is radius authentication against a radius server available within LuCI already. Radius itself is huge with a lots of packages required and does make sense only for larger environments but not for home users (IMO). Since a while there are better options for home users (with more needs) in place (Individual per-passphrase/per-MAC Wifi VLANs using wpa_psk_file (no RADIUS required)).