I assume this is due to AVX2 being rare in general-purpose software, so the design "one core is running AVX2 -> switch large part of CPU to AVX2 mode" doesn't h

I assume this is due to AVX2 being rare in general-purpose software, so the design "one core is running AVX2 -> switch large part of CPU to AVX2 mode" doesn't hinder use cases where you are hammering all cores with AVX2 code.