On the iOS side I am certain paying for apps is far more common, though of course you can also fill up on free apps (and those free app devs still make a killing).
My daughter has all free apps, probably four pages of them. But I have quite a few paid apps as well as free. Eight pages, two of them full of folders containing the maximum nine apps or nearly that. Easily a hundred installed, not counting the separate set on my iPad.
Ryan
Sent from my iPhone