And exactly here the misconception starts. It does not create a “derivation”. It just mimics an environment that can be used to build a given derivation.
And as pointed out in How to use `nix develop` within a GitLab CI pipeline? - #2 by NobbZ, it is possible to use nix develop in CI.
CI Services that allow you to change your shell for a job/step with a custom command, can use nix develop even as a “shell”.
Though you will never actually able to “build” and “install” something that is like what you enter with nix develop, as it simply isn’t able to set env vats some how.
Anyway. Most if not all of the posts since What would you like to see improved in Nix cli experience? - #10 by nixinator are probably off topic in this thread, and I’d ask @moderators to split them out.