Only for applications that are well-behaved. Nixos doesn't enforce any of the isolation, which is something that disappointed me when I tried it the first time.

Only for applications that are well-behaved. Nixos doesn't enforce any of the isolation, which is something that disappointed me when I tried it the first time. If a program wants to mess up another program's private directory, they can do that without anything stopping it. I then realised that having actual isolation was never even a goal of the project, so I've never bothered to look at Nixos after that. The only project on Linux that provides a practical solution to this is Qubes OS. I use it, but there are limitations that prevents it from being used by a lot of people. The fact that applications don't have GPU support is a big one. One may suggest Flatpak as well, and it's a good solution when using properly packaged software, but if I want to do development and use various tools without necessarily trusting all of them, Qubes OS is really the only way I can do that.