I have a NVIDIA shield which is the best Android media player despite being pricey. It has potential for games but I haven't really seen it. One problem is that the internal storage is not enough to play a "real" (say 5GB+ game) and that external storage doesn't seem to be terribly reliable despite trying a USB-attached "gaming" SSD.
And of course the games I have for it are Doom 3 (can't play because the license server won't let me), Pac Man 256, and Retroarch. I played through Record of Agarest War years ago but they took it out of the store.
I have a refurb XBOX One with a 2TB hard drive, it's probably about 40% full right now. I also have a jailbroken Nintendo 3DS with a 32GB card that is about 70% full and has a huge number of games on it including some of the largest that came out for that platform.
In terms of high-end mobile games though, I have some interest in playing titles like Genshin Impact, Nikke, Fate/Grand Order and Azur Lane on my 32GB iPad. A game like that is usually a 2GB download from the app store and then it installs another 10GB worth of levels. Practically I can fit exactly one of these titles on my iPad but then there is no staging space left to update iPadOS. Often I want to play and find it has to download the 10GB package again which is not 100% reliable even at the office.
I wind up uninstalling those games because it just isn't fun.
You could make a good 12GB game in most genres and I could be happy if I could just play 1 game without drama, but having 3 games that size installed would be good.
I think though the royal road to software for you would be to attract ports from other platforms, if they don't have to do a lot of work getting storage requirements down they'll be more inclined to do it. It may help that a lot of work is already being done to shoehorn games for the Switch.
I was imagining that you'd convince the publishers to port games. It could be something new or something classic: imagine GTA: San Andreas on Android TV or the Shield.
And of course the games I have for it are Doom 3 (can't play because the license server won't let me), Pac Man 256, and Retroarch. I played through Record of Agarest War years ago but they took it out of the store.