UML is not documentation, it's code for people who can't read code. UML diagrams offer no additional information to someone who already can read code (and write readable code). They are training wheels. Mature bike riders don't use training wheels. Mature teams don't write UML -- they write code instead.

Other forms of documentation have their own tradeoffs, but I was not discussing those. You're the one who automatically equated UML with all possible documentation.

> to build good software they’ll want to capture requirements, communicate with other teams, and test their software

UML is awful at all of this.

> At the end of a successful day, I should have ...

> “smart people like me do X and not smart people do Y”

You don't see the irony here?