Not to mention, rarely does app size register to clients, PMs, bizdev in terms of a worthy task. Only when you end up at the top of the app sizes list is time given to optimize.

We work to keep down app sizes and offer line item tasks for app size optimization on updates, noone finds it needed until they start to risk being near the top of the app list on a users device when they want to delete some apps.

In games, many toolkits/engines like Unity and Unreal in mobile also add quite a large chunk. Building your own engine is rarely an option anymore in terms of competitive launch. Many games built with Unity/Unreal even with moderate assets can reach 200-300MB easily and easily creep up further on updates.

If you need to advocate this, it tells a lot about how much app devs care about the issue.

I can forgive games for sacrificing size in favor of high-res animations and a blazing fast graphics stack, but I don't think LinkedIn, for example, is in need of particularly fast graphics.

Given that, I don't think it's unreasonable to consider using a library to do it better, although you have to weigh the increase in apk size. The standard crypto libraries on the phone are great if the features you need were released 5 years ago, but if you want consistent behavior across Android versions and manufacturers, you need to include that yourself too.

Unlike Android, end users can't clear it, though backing up and restoring your phone does that...

It seems that most users don't really care nor use all that many apps.