Perhaps with a more robust OS, such as Linux or macOS the battery and thermals would just not suffice?
I mean, an iPad is basically a larger phone, which I think can get hot enough if pushing it to its limit
Also I don’t think the RAM would be enough for intensive tasks, the device as it is could be pretty good for gaming though, if only the title list wouldn’t be a shit for the most part.
But at the same time, a MacBook Air doesn’t seem much bigger compared to the biggest iPad available.