The privileged ISA is still a draft and is supposed to be finished later in this year. The privileged ISA is needed to support operating systems. There are projects out there targeting this kind of processors, for instance lowRISC.
It can run TempleOS :)
That's just because microcontrollers are cheaper and easier to produce. It's going to take someone with deep pockets to make a desktop competitive RISC-V processor.
Lowrisc.org is between those two extremes. Nothing shipping yet though.
Nvidia had a presentation at the risc-v workshop a few years back. I think they are building chips with it. Nothing the regular programmer sees though I don't think