It's a very difficult choice!
A really big benefit to the 13" model is that it is so much better as soon as you decide to do some multitasking, like split view. In addition, even when not multitasking, in some fullscreen apps you really benefit of the extra screen real estate. I opened Final Cut Pro on a M2 11" model and 12.9" model side-by-side. The 11" felt a bit cramped, while the 12.9" really felt much better. Than again... I'm not a professional video editor, so does it really matter?
On the other hand, the 11" model has a slightly more favourable aspect ratio which results in slightly smaller black bars when watching videos. It's obviously also more portable. The display obviously is big but not that big. It makes me wonder: iPhones are bigger than ever nowadays. Won't I be more tempted to quickly grab my iPhone instead of the iPad? (While with the 13" model, you'll really benefit of features like split-view).
Tuesday I was certain I would go for the 11" model. Yesterday, I decided to go for the 13" model. I might alter my mind a few more times before next week.
So many things to consider, but right now what's pushing me towards the 13" model is that I also generally will use it around the house, which means size is less of an issue for me and it is more than 100 grams lighter than the previous model - bringing down the weight difference between the 11" and 13". Which means that when I do bring it with me in a backpack, I'll likely be less bothered by the weight and its size.