I need a desktop 90% of the time. I need a laptop 10% of the time. Therefore, I must have a laptop. I only need 1 screen 99% of the time (there is ONE use case where I use dual screens, only a few times per year, having laptop is advantageous because it has a screen built in), especially when using my LG UltraFine 5K (The "Apple" one).
My 16" MBP Intel is in Clamshell mode 90% of the time. But, i do need a laptop occasionally. And the second screen occasionally.
So that is why i have a laptop and use it in clamshell mode most of the time. I have a feeling that is a common reason and answer to this question.