That's similar to the aspect ratio of the 11" and how it would have made a noticeable difference over the 10.5".
The aspect ratios are different enough to be noticeable.
10.5: 1.33:1
11: 1.43:1 (similar to A4 paper)
8.3: 1.52:1 (similar to the old 3.5" iPhones)
Also, assuming your signature is still accurate, you have a 12.9" iPad Pro, a 10.5" Pro, an iPad Air, and now a mini? Do you find use cases for all four? I have a 12.9" iPad Pro and am considering a mini, but I feel bad because I can't really justify it given the Pro has the same functionality.
The iPads in the sig are the ones that actually see regular use. I kept some old ones that I don't use much (for old iOS or apps or beta testing).
Pro 12.9: Used every workday in the office docked on desk as a 3rd display for PDF markup, emails, chat/messages, phone calls, etc. Doesn't really see a lot of use at home unless I'm watching videos or reading comics.
Air: Everyday carry (purse). Used a lot for web browsing and ebook reading primarily at home but also hospital waiting rooms, around the office for quick reference and note taking, etc.
Pro 10.5: Used when the Air is charging. Battery's pretty worn out so this one is used least and mostly serves as backup to the Air. The 10-11" iPads are my goldilocks size.
I plan to use the mini as everyday carry instead of the Air. I don't expect it to see as much use as the others (kinda why I wanted a cheaper 128GB config). However, it has the benefit of being more easily pocketable (jacket) so I can always carry it around the office. Right now, the Air just stays in the purse at my desk unless I already know beforehand it'll be needed so either I'm stuck with just the iPhone or I'd need to walk all the way across the building to get the Air.
And hey:
iPhone SE 256GB $349+$79 AC+ + iPad mini 6 256GB $799+$69 AC+ = $1295
iPhone 13 Pro Max 256GB $1199+$199 AC+ = $1398
The small iPhone + iPad mini combo is still cheaper than the Pro Max while giving me a notably bigger display option—one that doesn't induce migraine attacks.