All of them? ...you mean the only one that existed before this console right?
sure it was on android ...and it was a portable device.
I expected that they would get out of the limitations of a OS meant for portable devices, such as android, when going to the route of a full fledged console. Using, who knows, another linux based OS, or even Windows 10 (since they work with Microsoft doing video cards for decades..).
But still android? ...meh