That's a really insightful view. Perhaps one can extend it to automated UI tests too: if it breaks a test by moving an element/adding a popup/changing the flow

That's a really insightful view. Perhaps one can extend it to automated UI tests too: if it breaks a test by moving an element/adding a popup/changing the flow/taking longer, then it would probably undermine existing users' expertise. What used to be a fragile test is now the canary in the coal mine.