What you are saying isn't wrong. But I'd like to point out is that the companies that buy "Chinese RISC-V MCUs" may not be the same ones who license Arm CPU IPs

What you are saying isn't wrong. But I'd like to point out is that the companies that buy "Chinese RISC-V MCUs" may not be the same ones who license Arm CPU IPs and put them next to logic from other suppliers on a custom built chip. For one thing, it is seen as risky nowadays to use Chinese IP in chips, ever since Mr. Trump said that the US government wouldn't buy certain Chinese tech. The bigger cost in chip development is verification, not design. If you use open-source IP, I assume you need to take on this burden yourself or pay someone else to do it. The cost for doing that may well be more than the cost to license an already verified core (Arm or RISC-V ISA).