I’ve been using my 2018 iPad Pro 12.9” as my daily driver for both work and off-work for the past couple of years and actually love the larger size. I’ve had previous iPads (Air and several generations going back to the original) and the 2018 Pro model is the first that doesn’t feel like it’s an oversized iPhone.
Yes, you have to be more deliberate and mindful of the size when holding it, walking around with it, etc., but it’s almost exactly the same size as a standard (North American) notebook or magazine, so it’s not like you’re holding a 21” oversized screen. What I really enjoy about it, is how seamless it is to go from using it like a computer when it’s in the Magic Keyboard, then grabbing it off the keyboard and using it in more traditional tablet form when I stop working.