I didn't write, nor do i maintain the software i use. for instance, i have a couple of old, but perfectly working web-UI for stable diffusion and LLM. If i, say, copy the folder to an ubuntu 24.04 server install, there's a real good chance it won't load at all. I can't fix that. I mean, i can, but i can't fix it for free. It's cheaper and lazier for me to just maintain the machine/VM for my own purposes.

So in the case of Nix, i am still unsure if, for example, i had a Nix config for some software (say whisper-ctranslate2), is that permanently portable? Is there a way to make it so? Right now, with stuff that needs a GPU, the only guarantee i've found is to either do pcie passthrough and use a CoW VM that does incremental backups to NAS, or, if the publisher provides, a dockerfile / container.

For nearly everything else, i use a rolling release server OS and keep stuff up-to-date. bleeding-edge sci-tech, being publish or perish, doesn't much care about the published code working much past the git push.

For comparison, every time i've tried to use a node.js distribution of a package, there's some blocker because a pulled-in library version is vulnerable, and i'm even less likely to be able to fix that than some C++ or python thing.