My first candidate for removal would be fragments. They don't help to componentize apps at all (at least not better than plain old viewgroups), but they can make life much harder with weird hidden bugs.
In Anvil I try to follow Square's approach, e.g. keep components as viewgroups and use a custom backstack to manage them as needed (e.g. back/home navigation, multi-pane layouts etc). Then you get just one activity per application and it's a big relief.
I am not really convinced. Fragments are not very helpful indeed but all the Android engineers I work with know their lifecycle pretty well and I don't even remember the last time I have seen a prod bug coming from them.
There is brilliant article from Squareup about that - https://corner.squareup.com/2014/10/advocating-against-andro...
In Anvil I try to follow Square's approach, e.g. keep components as viewgroups and use a custom backstack to manage them as needed (e.g. back/home navigation, multi-pane layouts etc). Then you get just one activity per application and it's a big relief.