I feel like The Mill is an architecture that deserves to succeed more than RISC-V, if only they would take the RISC-V openness approach instead of patenting it.
The Mill architecture has no desire to be commercialized. I honestly don't know why anyone would care about it. Sabotaging RISC-V for the sake of this isolated island project is a very weird trade off. I'm sure adopting RISC-V will save a life or two. With the Mill project you're unlikely to see it even be manufactured at scale.
Mill has been slideware for as long as I can remember, and I don't see that changing. There are some interesting ideas there that I think would be interesting to explore for comparch researchers, but I have very near zero faith in Mill Computing ever producing something people can buy and use.