Apple has simplified product lines, the iPad especially so. The only difference between iPad models for a given year* are capacity and data network.
In contrast, the computers are available with customization choices that affect performance (GPU, CPU, HDD or SDD storage) and thus listing more detailed "supported on" requirements with CPU and GPU specs is still relevant for the Mac.
* Yes they're still selling last year's model at a discount, but it'd still be known as the prior year.