That is the sole reason I chose iOS this time around is that the software is same across the board. Interoperability within apple ecosystem is bar none.
I like standard Android OS from google and I don't know why vendors try so hard to gimmickify standard Google UI. There are things that they should be able to do. But they should be there upon request, not by default and with no obvious way to opt out of crappola of vendor modifications.
They gimmickify it because they don't want to be just making commodity devices on Google's behalf. They want people to notice a difference between their handsets and others and to be deterred from switching to something that looks unfamiliar.
I like standard Android OS from google and I don't know why vendors try so hard to gimmickify standard Google UI. There are things that they should be able to do. But they should be there upon request, not by default and with no obvious way to opt out of crappola of vendor modifications.