Well, at least there are many independent chip providers, and that they use the same ARM architecture (i.e. detail design specifications, etc.) even has the adv

Well, at least there are many independent chip providers, and that they use the same ARM architecture (i.e. detail design specifications, etc.) even has the advantage that tools and know-how are re-useable by the companies using these chips (and that each of these chip providers has the ARM detail design at hand is even an advantage compared to RISC-V, where "only" the ABI is open source); in contrast MS is indeed a single provider keeping the source code of most of its products closed (which virtually makes it a potential "single point of failure" for a large market).