Don't know about any statistics that cover specifically that segment, but when it comes to new device shipments, it has been reported that iOS + macOS surpassed Windows + Windows Phone already in 2015, and it is estimated that this trend has continued since then.

PCs. iPhones are very us centric ... the rest of the world dominates unsurprisingly.

That's probably a good question. Those who are actually pushing the hardware in both camps are most likely the minority, as opposed to those who are working with glorified web views.

But AAA on a Windows desktop commands $40-60, whereas AAA on mobile commands < $8 +/- scuzzy IAP schemes.

This list[1] is quite a bit different looking from this list[2]

[1] http://store.steampowered.com/search/?filter=topsellers

[2] https://www.apple.com/itunes/charts/paid-apps/