Well, you basically summarised why I decided against spending any amount of time with NixOS. For me it is just too niche, too different and I can’t see any benefits of choosing NixOS over more common and established distributions.
Instead I went to Fedora Silverblue and Flatpak and decided to learn their quirks. I am actually quite happy with Silverblue now and some of my knowledge (Flatpak) can be applied to other distributions as well. On the server I am in the process of moving from Ubuntu to Debian + containers due to Ubuntu no longer meeting my needs (inflexible disk encryption in the installer, Canonical’s behaviour, future plans with package management, etc.).
Why did you choose to dive into NixOS in the first place?
Btw.: I don’t want to discourage anyone from choosing NixOS or any other Linux distribution. I am sure they are perfect for people with different needs than mine!