Running programs as root security implications

In a single user system, lets say my desktop pc. What are the security implications of running unknown scripts and programs as root.

I'm obviously aware of the system administration aspect of things. Software running as root can completely bork my system.

But from a data privacy point of view, whats the difference between running a program as root or not. In both cases a program can access my files/data, install malicious software, autostart it if need be and whatnot.

The only thing i can think of is that is i create a different user for storing sensitive data. And/or use selinux or whatever. Then running programs as my own user won't be able to access my files without my password to switch to the secret user.

One other thaught is that finding some malicious software is easier if it didn't have root to install itself as some kernel module or something, or even a custom Linux kernel.

So unless someone can give me a solid data privacy reason for not running stuff as root, im gonna correct people that use that as an argument.

And if you are using a declerative distribution like nixos like me, then borking your system is fixed in 10 minutes with a fresh install. Unless your malicious code managed to break/overheat your hardware, in that case rip.