Conda does not solve the problems of deployment and they don't have any reproducibility guarantees. That's not surprising considering how Conda binaries are built.
I use a Guix manifest for every project, which describes what dev tools and dependencies I want. When I enter a directory the shell automatically evaluates the manifest and all my tools are ready.
With tooling for deployment I prefer to heed an adaptation of Greenspun's Tenth Rule. Neither Guix nor Nix are really all that "complex" from a user's perspective.