I doubt the total chip number for the industry though - Intel alone ships ~100M. But it's clear Apple is very likely the largest manufacturer of CPUs.
* Correction: MediaTek shipped 350M units in 2020 and Qualcomm shipped 319M (due to the Trump embargo on China). So Apple is up there competing with manufacturers that sell their chips to anyone who will buy, but it may not necessarily be the largest.
Manufacturer? Where are Apple's fabs located at?