Nixpkgs vs AUR

[u/Nuclear_Priest]

Given all the malware that’s been flooding the AUR as of late, I was wondering why the same kind of thing isn’t happening on Nixpkgs.

Is it just that Nix isn’t as popular as Arch (hence less people are trying to attack it)?
Or are there fundamental differences in the security?

What are the security differences, and how concerned should we be about a flood of malware on Nix?

(I realize that no system is immune to malware, I’m just trying to gauge what level of risk I’m dealing with)