Tried a 15 Pro. My test was to use it exclusively for 10 days to see if I could get used to it and then go back to the 13 mini for a day or two before deciding if I'd keep it or not. There are a lot of things I liked about the 15 Pro. Screen was better, it was faster, camera(s) better, battery life was better, upgraded materials, I dug the action button etc. I did get used to and get better at doing things one handed. But then when I went back to the 13 mini after not using it for that time I instantly remember why I prefer the smaller size in the first place. It just felt better in the hand, it was so much easier to use one handed, it fit better in my pockets (like my jeans or even in workout shorts). So I returned the 15 Pro and saved my self $1K!
When I'm out and about I'm pretty active and I prefer the smaller size over the functionality of the larger iPhone. I don't often enough do the things when I'm out that takes advantage of the larger screen/size. Another huge factor is that I am privileged and also have various iPads. So in many cases where other people would use their iPhones at home, I reach for my iPad which for those tasks are MUCH better than any large screen iPhone would be anyway.
Bottom line - I could use a 15 Pro if I HAD to. But for ME using the 13 mini fits my lifestyle better and besides that I already have it and don't have to pay for something else!
IF Apple was to produce a slightly larger than mini but not as large as regular Pro (say a 5.8/5.9" version with the slimmer bezels/body vs what the X/Xs/11Pro was), I'd probably be really happy with that.