I didn't say "it suddenly breaks". I said I have more issues with it, which is decided different from "it just works", which has been my experience on CachyOS. Specifically I mean issues with installing (up to date) software, or using software that has requirements that I just can't install the required version cause the repo has a version from 3+ years ago. Not everything has to be "bleeding edge", but being so stable that everything is utterly outdated is also a kind of unstable.
Sometimes this goes so far that the "stable" version shipped by debian is already unsupported upstream with all the security implications that entails (I had that once with PHP, I think).