a UI should offer everything a user can do in a given moment, readily available, nothing hidden behind more than a single menu.
That would be a nightmare for any sufficiently complex software. Can you imagine how dense the UI would need to be for something like Blender or even Excel if literally every possible option of "things available to do right now" had to be at most two clicks away?
I don't really disagree, at least in principle. You're absolutely correct that workflows should be clear and developers often do not make good UI/UX. You just didn't really qualify your original statement with any of that and made it an absolute, but you've clarified now and I'm pretty sure we agree.