The fact that we're 15 years into smartphones being popular and that phones & computerized address books were basically fully-solved interfaces long before those took off, and they're still fucking around with phone app UI in big ways, is a sign of some kind of institutional or industry-market failure to me. Or both. Allowed, I suppose, because Google's market position (i.e. monopoly across several markets) both gives them the surplus profit (i.e. rents) to fuck around and waste money on harmful to users crap like phone app redesigns, and insulates them from any actual threat to their profit due to those bad choices.
When we rename or remove a function from an API, that's a breaking change, any dependent software will no longer work unless it's modified to take that change into account.
Similarly, when we move, rename, or remove a UI element, keyboard shortcut, or visual affordance, that should be considered a "breaking change" for our dependents, the humans on the other side of the screen. And in the same way, we should avoid making such changes unless the long-term benefit of doing so outweighs the short-term cost. Plus, users will know that moving from 7.x.x of your software to 8.x.x will require them to relearn some aspect of it.
Before I could give her the freshly grandparent-proofed device, said video calling app upgraded on my parents' PC first and changed literally every single element of the UI beyond recognition. To someone the age of my grandma, that would be literally like bricking the device remotely, because none of the buttons would look the same, and she would not be able to work out how to use the new interface.
STOP CHANGING THINGS! Even if the new UI is better (debatable), some people just like or rely on a particular layout to operate the device or app. Don't rearrange without giving a ~permanent setting to use the old layout.