>>881190 (OP)
I've run the following operating systems over the years, in no particular order: DOS, FreeDOS, Windows 3.11, Windows 95, Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8, Windows 10, Mac OS X 10.5-10.9, Debian, Ubuntu, Mint, Gentoo, Arch, Fedora, CentOS, LFS, openSUSE, Slackware, FreeBSD, OpenBSD, NetBSD, DragonflyBSD, OpenSolaris, Minix 3, and Plan 9. I'm sure I'm forgetting some.
Something I've learned over the years is that all operating systems suck. They suck bad. Whether they're proprietary (Windows, Mac OS X) or FLOSS (Linux, *BSD), they all suck. They suck in different ways, and to different degrees, but in the end they're just various levels of garbage. Especially if you do anything out-of-the-ordinary for the system, you'll rapidly run into frustrations, brokenness, corner-case bugs, and other bullshit. I have yet to run into an OS that I haven't hated something about. Debian stable is too old. Sid is (too) unstable. Testing doesn't get timely security updates. Arch is insecure out of the box. It's easy to get into Portage USE flag/dependency hell if you're doing anything unexpected on Gentoo. A bunch of FreeBSD ports are broken or fragile. OpenBSD is slow. Windows is a bloated, slow, insecure, privacy-invading blackbox. Mac OS X is full of bugs, which you'll encounter the first time you try to do anything with it but update your blog from a Starbucks.
I don't blame the creators of those OSs entirely. Writing OSs is hard. Writing good software is hard. And for the vast majority of normies, most of those operating systems would be adequate: if they can run a mainstream browser, listen to music, and transfer files to and from their smartphone, they're happy.
I don't use Debian anymore, so I don't have a horse in this race, but my point in all of this is that you're probably going to find something you hate about NixOS. I've resigned myself to never finding the perfect OS, or even one within spitting distance of perfect. Sometimes I think the best thing to do would be to drop this machine in the local lake and pretend that the microcomputer was never invented.