You might be selling it a bit short. I am not a Nix user, but like you I’ve played around in a vm. The value proposition I see for “normal” users is when you end up tuning and configuring your system just the way you want it (everyone knows what I’m talking about–it happens over months or even years). In nix, you have to do those changes in the config so you can literally take that one file, plop it somewhere else and it’s your computer.
Likewise, I’ve been on this install of Pop for years and for several upgrade cycles. The amount of cruft; things I’ve installed and don’t use, config changes I made while following a tutorial then forgot about, manual tweaks for things that have been officially patched, etc. it would all be in a nix config for me to just… remove.
So I see that as the benefits of it.
That said, it definitely gives me vim vibes. Where the learning curve is pretty steep but once you master it, it’s close to tech Nirvana. Again, since I don’t use it I can’t say that for sure. Maybe one day I’ll have enough time to devote to it to really dive in. Right now, it’s frustrating to use because everything is harder and there aren’t many guides on how to do basic things like get dash-to-dock plugin working on popshell. Or even install and configure neovim. Ain’t nobody got time for that right now.