Root access takes agency away from you and gives it to 3rd party software. It doesnt expand freedom at all, it just allows other software to abuse the user.
With a proper security model and verified boot, you can be certain you, the user, are running exactly the OS you expect to run. You can also properly revoke permissions to software and gate access as you see fit. With root, you cannot guarantee you are running what you expect and apps have to exploit much less to get root access, or just keep root access if given by the user. You cannot revoke godhood, it can just lie and say you revoked it. There is nothing enforcing any security features.
With a proper security model and verified boot, you can be certain you, the user, are running exactly the OS you expect to run. You can also properly revoke permissions to software and gate access as you see fit. With root, you cannot guarantee you are running what you expect and apps have to exploit much less to get root access, or just keep root access if given by the user. You cannot revoke godhood, it can just lie and say you revoked it. There is nothing enforcing any security features.