You are really only correct in your last point as the advantage of RISC-V is to the company implementing their own core, not to the end user.
The reason is that CPU cores only form a tiny part of the SOC, the rest of the SOC is proprietary and likely to be documented to whatever level the company needs and the rest if available hidden under layers of NDA's. Just because the ISA is open source does not mean you know anything about the rest of the chip.
saying that, the C5 is a nice SOC, and it is nice that we have some competition to ARM.
The reason is that CPU cores only form a tiny part of the SOC, the rest of the SOC is proprietary and likely to be documented to whatever level the company needs and the rest if available hidden under layers of NDA's. Just because the ISA is open source does not mean you know anything about the rest of the chip.
saying that, the C5 is a nice SOC, and it is nice that we have some competition to ARM.