I worked in small and large game companies for over 20 years and this does not surprise me at all. A modern AAA title involves 100s of people, whereas a small independent can be less than a dozen. At scale a company can spend millions on advertising reach, on graphics pipelines and content creators. What they are bad at is small things and risk. If you spend $1b developing and marketing a game you must ensure it appeals to the widest demographic possible. Unless there is a clear market of hundreds of thousands then it's really hard to shift even the meagre amount of resources it would take do the actual port. And then, as a large company, you need to train people to do support, you need legal people working with the platform for all kinds of shit from placement and proper use of logos to compliance with app store rules.