The downside is that the approach works best when packages are aware of the Nix approach. But the packages have not been written with Nix in mind, and some work is needed per package to adapt to the approach.
It's a true wonder but much like the AUR (read: Archlinux User Repo), it's great 80% of the time when projects have reasonable popularity or committed (even 'niche') support.
It's honestly a treat for personal use if you have the mind of a tinkerer, but it's a difficult proposition to sustain in business (you basically end up vendoring yourself if big enough).
Nix has a very different proposition that solves from the "inside" a problem that is currently usually solved from the "outside" using e.g. Ansible in ops/infra, or Vagrant in dev.
In my perspective, the outside/black-box solution is ultimately brute-force, plain and simple. It works because it scales well, because copying data is cheap enough (re. deduplication, delta sync, etc) You hit limits when systems grow older and complexity creeps in no matter what however, it's an approach that requires a blank slate every now and then.
But the inside package approach is elegant in that it's absolute, it's not conjuring a black box that "should just work" if Ubuntu18.04-387lts-32-1.989-2a and my_fav_package.1.1.1.9.3.5-f work fine together, this time around. Sure, there is testing but we're back to the popularity/support limit.
In the end, in a world where some of the stack is basically nailed and can be modularized with clear forever-true expectations of I/O (the content, not the hardware), then Nix eventually prevails— but we really have to evolve "LTS" for what it means (like we'd do in construction, electricity, plumbing...), and not a half-trendy windmill / rat race. But we have to think of those systems that could transfer almost-as-is well from now to 2050 or more, not 2025-2030. It's not impossible, it's what COBOL did, does as we speak.
I think something like Nix could help shift perception in the right direction, but I expect mindsets to take a good part of the decade to change deeply, if it happens.
Yes, absolutely. Although to be fair, CUDA is a royal pain (although way easier) even on more standard distributions (supporting multiple versions seamlessly is hours and hours of fun and breaks all too easily) and is behind the great majority of time “wasted”. NVIDIA deserves a lot more flak for this than they receive.
Part of the reason is probably that you need the proprietary drivers to use CUDA efficiently and as they are not in the (upstream) kernel you have to use some other tools, like unofficial repositories or the native installer (which doesn't always play well with the OS package manager, system upgrades, etc.). It's a real PITA.
That's really a flaw with how those packages have been designed rather than a flaw with Nix. We've known that it is a terrible idea to put everything into global directories, edit `PATH` and so on for literally decades.
