If you’re looking for a new daily driver, look at Fedora Silverblue. I also started on arch, and have been in nix for the last two years, and I’m planning to switch to Silverblue in the next year

Personally I’d be worried there’s a transient disk issue. I’d ensure my backups are good and files aren’t being silently corrupted. I assume you’re on an NVME, they tend to fail instantly, but sometimes you’ll get transient file errors beforehand (like not being able to open a system library). Look at something like debsums to start with maybe.