There are two different models of 6.1” iPhone, one is mid-tier (iPhone 12), the other is at the top of the line (iPhone 12 Pro).
That’s true regardless of the existence of a 6.7” iPhone 12 Max or a 6.7” iPhone Pro Max.
Maybe this will help:
Apple makes two different 13” notebooks, the MacBook Air and 13” MacBook Pro. The Air is the lesser featured, mid-line, while the MBP is the top of the line.
That doesn’t change just because Apple also makes a 16” MBP. I have no interest in a 16” notebook, because I can’t use it on an airline tray table. But I want the best, most featureful, top of the line 13” that Apple sells. So I know instantly which to buy: the 13” MBP. I don’t even need to compare them, Apple’s naming scheme makes it clear.
In any case, Apple will do what they want with their naming, no matter what you and I think about it.