The first step in antitrust is to define the market. It seems unlikely that desktop/laptop would be considered a separate market - mobile is just too capable (how do you even draw the line between an iPad Pro and a laptop?) But even within desktop/laptop you have Apple plus Chromebooks and to some extent Linux as substitutes. There were no serious substitutes in the 1995-1997 time period that led to the antitrust proceedings.
Phones are not capable in the same way. And I think this number already counts chromebooks. Let me know what your revised number is for ipad pros.
> There were no serious substitutes in the 1995-1997 time period that led to the antitrust proceedings.
Macs were just fine then, and they're just fine now. They couldn't run all important business software then, and they can't run all important business software now.