You know some of us old timers still remember a time before people just totally abandoned the concept of having functional definitions and iso standards and things like that.
Funny how we haven’t done anything on the scale of Hoover Dam, Three Gorges, ISS etc…since those got thrown away
User Experience also means something specific in information theory and UX and UML is designed to model that explicitly:
https://www.pst.ifi.lmu.de/~kochn/pUML2001-Hen-Koch.pdf
Good luck vibe architecting
Notably, the terms "UX" and "experience" are not present in that document. UI and UX are different things. UX is a newer concept that is more based on observing users and their emotional reactions to using the product.
UML and functional definitions and iso standards are still important, it's just not UX.
Good luck never observing users using your product. Not everything is a space shuttle, recall that we are talking about toothbrushes here.
Ask any person to go and find a stick and use it to brush their teeth, and then ask if that "experience" was the same as using their toothbrush. Invoking UML is absurd.