My eyesight is ok. Getting worse. I only compared the mini text size to the 12.9’s, which was a little less than 25% bigger on this site. But I think the other iPads should be the same as the 12.9” since they share the same 264 ppi. Only the mini has 326 ppi.I think you probably have much better eyesight than I do. To me, going from 9.7" to 7.9" already requires 20-25% adjustment in font size. I use my iPads in landscape so even on 9.7", there's more scrolling on websites than I'd like already. I prefer pagination to scrolling and I find reading in 2-column lansdcape mode with my favorite ereader app on mid-size iPads is pretty perfect.
Also, in my case, 300g is still too heavy for single-handed use (RSI). Even the Kindle PW3 (205g) is stretching it comfort-wise. All my purses fit mid-sized iPads just as well as the iPad mini so the mini doesn't really give me any benefits over the mid-size iPads.
Going by my large extended family, the ones who have good eyesight are content to stick to their smartphones. Those with not so good eyesight prefer mid-size iPads or even bigger. The only small tablets I see are Amazon Fire but I expect that's more because it's ~$50 ($25-35 on sale) rather than because it's small.
But sure, like I said, if one already scrolls more than they want, obviously going smaller doesn’t make sense. If you like having double pages on the screen, that’s a valid preference. iPad mini wouldn’t be for you.
That’s interesting. Eyesight acuteness is a gradual spectrum, why do you suppose there’s such a big jump in preference from smartphone to midsize iPad in your family?