Has anybody ever touched the top corner of an app and said “yep, I totally meant to do that and wanted to scroll to the top of the document/ feed/ whatever.”

Because I haven’t. This “feature” sure seems to cause a lot of unintended behavior which sounds a lot like a bug. Who is out here developing stuff like this? Please stop! Do some real UX research with how we actually use the apps!

Modern UX is all about performing unexpected actions depending on what the user does or doesn't do.

Smartphone users are basically expected to just know before first try that shaking the phone will trigger a bug report in some apps (but not all, as that would cause unwanted predictability)...

The current design principle for UX is to corner a rat and see how it reacts. That then is interpreted as to what should happen when a user is "holding it wrong". But you may not reuse the rat decisions because again - no predictability! Ever!