What I’m getting at is there are factors that affect the broader market. Having more people and companies able to work on processors means greater possibility of variation, and therefore has an evolutionary advantage.
There are three x86 companies, and there’s not likely to be any others. VIA is barely worth talking about. AMD is currently killing it, but it wasn’t always that way. Over a decade ago, a combination of bad decisions at AMD, good decisions at Intel, and underhanded tactics at Intel made AMD nearly collapse. Intel looked smug on its throne, and sat on the same fundamental architecture and manufacturing node for a long time.
This was a bad situation for the entire computer industry. We were very close to Intel being all that mattered, and that would have meant severe stagnation. ARM (and RISC-V) being more viable helps keep that from happening again.