i bought my m1 pro (16GB/1TB) macbook pro as a laptop only, whilst having a fairly high end desktop. however, the ownership experience of that was “almost but not quite desktop replacement”.
i upgraded to an m4 max with 64 GB to get more RAM and better GPU to basically be a do everything machine for me, expecting to decommission my desktop.
which it mostly has. i still play some games on the desktop, but for the most part my m4 max macbook can do it all, well enough. so the primary reasons for me were GPU (not quick enough, no RT on the m1 pro) and RAM (16 GB was enough for what i was using it for, pre LLMs, but now i want a lot more).
basically m1 pro was a taste that made me want more. if i had bought an m1 max originally, i’d probably still be on it for another year, waiting for m5 max.