You’re ignoring context. Yes, rooting let’s say, a stock OS on Android does give you more control, including things that can secure it more, but that doesnt change the fact that it does open holes for both physical and remote exploits that would go after system level changes. Thats not debatable, thats simply howba *nix/BSD based OS functions. Thats also ignoring that having the root acct enabled means leaving the bootloader unlocked which means no verified boot, anybody that attempts to claim thats not a gaping security issue has no place commenting on mobile phone security.

Thats why most *nix based OS’ starting disabling root accounts by default and want you to use sudo instead.