* Serious question. Apart from the freedom and control aspects of the Open Source model, what is solved with an open source CPU architecture or what are the benefits?
I can see being able to spin your own chips would enable an OEM/ODM to keep producing the same old design indefinitely where as reliance on Intel/AMD/Samsung/Mediatek means you have to refresh your design. That could be both a benefit and a detriment depending on how you look at it.
The freedoms from the Open Source model is substantial enough to make it attractive on that basis alone, just as for Linux/BSD. One example is Western Digital transitioning to RISC-V for their hard drive controllers. I would imagine being able to add your own instructions without having to deal with NDAs and non competes with ARM will be attractive to a lot of OEMs.
Just like with Linux, it's difficult to anticipate what intersting things will come out of RISC-V, but one interesting example is a formally verified RISC-V core, picorv32: https://github.com/cliffordwolf/riscv-formal/tree/master/cor... (presentation here: https://www.youtube.com/watch?v=VU97ffHF_IQ). According to the author, this core will power safety critical applications at a synchrotron: https://theamphour.com/374-an-interview-with-clifford-wolf/