> I wouldn't expect the microarchitectures that achieve this performance to be free (in either the "gratis" or "libre" senses of that word)

I agree with you on this as an eventuality of risc-v. But my casual following of the space leads me to believe that a high-performance open baseline of these architectures will be available and customization/special purpose of these archs will be for purchase.

I'm hopeful some of the benefits will be contributed upstream.

As long as there is some competition in the architecture space (ARM, x86, risc-v), the more likely builders will share gains upstream to compete against rival platforms.

That's my wishful thinking at least.