The easy answer: Google simply does not care. Some mix of: they don't measure it, they don't look at it, they don't goal around reducing it, nobody's performance review is going to be better because they reduced it, no director is asking product teams why they're increasing the app size. It's not surprising why these companies don't care, because it's a tragedy of the commons. The better question is why is Apple allowing these companies to ship apps that unnecessarily take up a meaningful amount of storage space?