Not the OP, but I work in consulting. When I was still hands on keyboard, this would have been very helpful for the clients who don’t provide their own hardware or environment for us to use. I also do work for extremely large organizations who have literally dozens of different stacks accumulated over the decades.

In addition, I play with all sorts of open source tools and they often come with their own tool chains and expectations. Python version management in particular benefits a lot from this level of isolation. Instead of figuring out the different version management tools for each stack I use a higher order environment management tool in Nix.

Some others are solving these issues with containers, and that’s a part of the nix strategy as well.