And the iPad Pro and iPad Air is distinguishable by TouchID vs FaceID and a better screen and smaller bezels. By looks, how are you suppose to tell the difference between two all screen devices?
The iPad Pro vs iPad Air seem distinguishable from each other, yes, but there's the iPad (A16) and mini muddying the lineup.
For example, the mini costs more than A16 iPad yet lacks a landscape center stage camera — but also has features the even more expensive Air doesn't, like true tone flash on the 12MP camera.
The iPad lineup is a mess, and spending more money can lead to getting less features. The iPhone lineup is pretty messy too, but the iPad situation is particularly terrible, and sales peaked years ago.
You can look at the Mini and tell whether you want a smaller iPad. Miniaturization has come at a premium forever.
And would you propose that Apple doesn’t offer a cheap iPad for bulk purchases and kids? A lot of computing devices are the same externally and distinguished by slower processors and less internal features.