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.