alt Hacker Newsnix develop ensures your dev env is the same as your build/test/prod env. At least with Python everything is a flurry of requirements.txt, Python versions, poetry, pyproject.toml, perhaps automated with direnvs, a hefty Dockerfile/docker-compose, and perhaps conda (ugh) along the way; lots of moving parts.
I have a project that's mostly Rust sprinkled with C++ libs and Python helpers and it's easier to manage than the average virtualenv. Everything builds with nix build, everything runs with nix run, profiler/debugger works, IDE detects everything on any of my computers, builds and links with CUDA on x86, aarch64, NixOS, MacOS, Ubuntu or Amazon Linux. nix build can even build a Docker image for the odd need of Docker, and I haven't tried but I'm convinced that if I import the flake on my nix-config it will be built into the SD card for my Raspberry Pi just fine.
It's even replaced Ansible for me, colmena all the way.
Pythonistas have mostly moved to uv, which solves much of the "flurry" you describe. Tools like Mise add more of the benefits ascribed to nix. And smolmachines' smolvms can provide better isolation than Docker. Just saying, TIMTOWTDI. Not hating on nix, just pointing out it's not the only game in town.