That was for a company that was struggling and had a much smaller customer base. As your market grows you can afford to tailor your offerings to better match different customers needs.

For the iPad, they basically have the good, better, best product line with the addition of the Mini for special cases. It's not really that complicated.

I'd say that the main complications are that the Pencil Pro only works on the Air and Pro and the keyboards have to fit the exact case size so they are not as universal as ideal. Most people don't need the pencil and not everyone needs the keyboards.

People keep bringing up this tired trope without realizing even in 2010 when Jobs was still around, you had three segments of all of their products.

Desktops - Mac Mini, iMac, Mac Pro.

Laptops - Air, MacBook, MacBook Pro

iPods - Shuffle, Nano and regular iPod

Phones - 3G, 3GS, and iPhone 4