Modern design doesn't really care for size either. There's a reason we did flat design in the past - we'd have fine control over how to stretch a button. Now we have things like glows, animations, 3D stuff, which doesn't compress well at all. As engineers, we've had to push against one glowing effect which add 2 MB.
There's also SDKs for everything, and these SDKs tend to add 10-20 MB here and there.
[1] https://developer.android.com/topic/performance/reduce-apk-s...
I haven't looked at installed package size in a while - and I use an app store known for lightweight apps!
Here's an example of a deep dive into Candy Crush on iOS/Android app size: https://www.emergetools.com/deep-dives/candy-crush-saga
P.S. If you think Android is bad, just check out iOS ;)
1. Big size impress management. 2. It's easier to blame SDK xyz for any issue than try to write something optimized and then debate with subskilled coworkers that are specialised in pushunderthebusing