Yet another reminder that Nix does not sign commits, does not sign reviews, allows any maintainer to merge their own code, does not compile all packages from source, and Hydra admins can absolutely tamper with builds at any time. It is a massive supply chain attack waiting to happen.
The Nix team is aware of all of this and made these tradeoffs intentionally to maximize package support and reduce contributor friction. Nix, for all its good design choices, landed on a supply chain integrity threat model that unfortunately makes it suitable only as hobby OS that must not be used to protect anything of value.
Guix at least signs commits, but individual maintainers are still trusted so it is not much better, so there really is no production safe nix based package tree I am aware of.
Nothing should advertise itself as secure while being based on nix.
Just because something is popular, does not make it safe.