Why is it not common UX practice to start ignoring user input prior to rearranging the UI, and only responding to user input once the layout has settled and perhaps after a short delay?

It’s very frustrating to reach for an option in a list, only to have the list repopulate just as I tap, inevitably on an undesired option

I’m not even talking solely about web design: even the Google Cast destination picker does this and it’s native Android code

Has Apple solved this over in iOS land?