I just got a new Android phone that iterated 1 version in the operating system and product. The old phone had a persistent triangle symbol to press for "back". Now that symbol is gone and I'm supposed to swipe from the edge of the screen for the same "back" function. Except, lots of apps use a similar motion for other functions, including Firefox for closing tabs. So, now I'm constantly swiping a few milimeters too close to the screen edge and going "back" when I want to close a tab, with few clear visual clues as to what is going wrong. This is just 1 of many UI fails on the new phone, very frustrating for me and I would guess extremely and unnecessarily confusing for "normal" people.