Apple has a perpetual license on the ARM instruction set, so they just pay a royalty per chip. Apple owning ARM would be a massive problem for regulators, as they'd be the sole source of chips to their competition.

MS and Google don't make chips, and MS doesn't even license any ARM tech (I don't think, they just make software and buy CPUs, they don't make any). They're a bad fit. Google's dipping their toes in it, but I don't think they're doing fully custom silicon. Most companies buy the rights and layouts, and tweak those layouts.

NVidia makes chips, but they don't make many mobile chips, and virtually no chips for phones compared to Samsung and Qualcomm. They're a better fit.