As Tablet Size Decreases... ➹

This matches my experience exactly. I have a theory about it, though:

Smaller tablets are convenient for many other activities besides web browsing, such as reading e-books, messaging and keeping track of social network activity - things that have a markedly different usage pattern and tend to have custom UIs.

Also, smaller tablets tend to be Android based and lower-powered, and the browsing experience on those sucks - more CPU helps considerably, but it’s still sub par.