This is an issue with nixpkgs not nix. Google could've just bootstrapped their own nixpkgs from scratch if they wanted to, see Guix (not a perfect example but still). Creating a whole new tool is still completely unnecessary
One could argue that creating Nix from scratch would be beneficial at some point. There's a lot of legacy hardcoded weirdness, Nix doesn't setup the containers with standard state of the art tools, the language is evaluated in a single thread and using values from derivations means a build blocks evaluation so it doesn't properly parallelise (nixpkgs bans "IFD" but it is useful for meta packaging).
Nixpkgs is more valuable than Nix at this point, but also quite vulnerable. In practice it has worked out reasonably well so far, I don't know of anyone who got "owned" because of Nix.
> using values from derivations means a build blocks evaluation so it doesn't properly parallelise (nixpkgs bans "IFD" but it is useful for meta packaging).
Not anymore with the introduction of dynamic derivations (experimental)
