Every time I see a linux installation with a mess in /opt because it's faster than making a package, I get annoyed.
It wasn’t that bad creating some new derivations my first week with Nixos, I was so used to Arch where I had maybe a handful modified pkgbuilds over a decade.
For better or worse it was a positive experience, especially when you usually already have a pkgbuild to go off of.
For random binaries, autoPatchelfHook works miracles.