I bounced off NixOS a few times as well. In addition to what you've said, I also didn't find it compelling because I already had a way of doing programmatic configuration and functional system management under Debian using my own scripts. So I didn't particularly see what converting everything over to NixOS configs would get me.
What made NixOS stick is running up against some problems where Debian itself was ill-suited and seeing Nix's power. For example, building an image for a Raspberry Pi can be done with a handful of config lines. Changing between a cross compile and an emulated compile is also a handful of lines. This kind of power feels akin to the general lisp / functional curse where certain things become so easy they aren't even well documented because once you understand the system it's second nature.
Another benefit - I've modified kernel source and I've written my own modules, but they always fell by the wayside due to the maintenance burden of a compiling a custom kernel package. With Debian, I would end up reading kernel source plenty of times to figure out what was going on, but it was effectively read only. Whereas with NixOS, adding kernel overlays is straightforward. Using what is essentially a source distribution plays to the larger philosophy of Free software.
What made NixOS stick is running up against some problems where Debian itself was ill-suited and seeing Nix's power. For example, building an image for a Raspberry Pi can be done with a handful of config lines. Changing between a cross compile and an emulated compile is also a handful of lines. This kind of power feels akin to the general lisp / functional curse where certain things become so easy they aren't even well documented because once you understand the system it's second nature.
Another benefit - I've modified kernel source and I've written my own modules, but they always fell by the wayside due to the maintenance burden of a compiling a custom kernel package. With Debian, I would end up reading kernel source plenty of times to figure out what was going on, but it was effectively read only. Whereas with NixOS, adding kernel overlays is straightforward. Using what is essentially a source distribution plays to the larger philosophy of Free software.