The biggest misconception is already in the title.
You do not have to switch your distribution ever.
You can achieve almost everything with almost every distribution. It might be a bit more work with this or that distribution than with another one, but its probably possible.
Personally the main reason to switch from Arch Linux to nixOS was Archs lack of ZFS support, and I wanted to drop BTRFS for a couple of reasons, of which one was its unreliability.
Other benefits I have from this transition is, that I have a centralised place and unified syntax to do my system configuration, and another place for the users configuration.
I can get similar recent programs as in Arch by simply overriding some attributes of a package. Updating software beyond what was given upstream in Arch always required me to manually check out from the ABS, tinker with
PKGBUILD files, sandboxing the build of the package and then manually installing that package, and probably even miss update builds when I forgot to set the revision counter in the
Similar for packages which you would like to have installed with a different set of flags than those provided upstream.