When I was developing a few pet apps, the reason was pretty simple. I was pulling in entire libraries for one or two functions. They were good libraries and good functions. I think multiple examples were Google-provided app development libraries that you roll into your app. Like, appcompat. Nobody can get by without appcompat anymore it seems, but nobody needs all of its functionality either.
Anyway, probably millions of lines of code, 99.9% of which I didn't call. There is a tool for stripping code that will not be called, and I reduced my apk's from ~20MB to ~1MB, although I wound up turning it off in the end because it was not trivial to enable correctly. (I was linking 3rd party binary libraries into my app which complicated things)
Anyway, probably millions of lines of code, 99.9% of which I didn't call. There is a tool for stripping code that will not be called, and I reduced my apk's from ~20MB to ~1MB, although I wound up turning it off in the end because it was not trivial to enable correctly. (I was linking 3rd party binary libraries into my app which complicated things)