I always talk about the difference between how good a device is when it’s actually in use, and when you’re carrying it around. For actual use open on the desk in front of you, the 16” MacBook Pro will essentially always beat out a MacBook Air, because you’re getting the benefit of the big screen, GPU, powerful CPU, excellent speakers and mics, etc.
By contrast, MacBook Air is about 20x better when closed - thin, light, small power brick, etc.
Which one is right for you depends an awful lot on how much you’re using it actively vs. carrying it around.
I see the 12 mini/pro max situation the same way. The more it’s in your pocket, the more attractive the mini becomes. The more it’s in active use in your hand, where you take advantage of the screen, camera, battery life, etc. the better the pro max looks.
I’ve been a +/max user since the iPhone 6+, but went for the iPhone 12 Pro this year explicitly because I wanted to spend more time with my phone in my pocket, and actively lean towards using iPad/MacBook for more tasks, I was finding myself doing too much on iPhone‘s small screen and keyboard.
It’s been good, and unsurprisingly, I profoundly prefer the 12 pro’s size/shape/weight in my pocket. But the screen is a little small when I’m actively using it. I have a tough decision to make this fall, the trade-offs are significant both directions.
TL;DR - the balance of size/screen involves hard trade offs.