There is no way today to build competitive opensource hardware, and RISC-V is not about providing opensource hardware. With RISC-V (or any other ISA) we remain mainly dependent on the manufacturer who implement whatever they want within your processor. I think you are expecting too much from RISC-V, it's not about winning a war against manufacturers, it's about providing a royalty-free high-performance standard ISA which makes it easier for newcomers to enter the market.

RISC-V is built around the idea that manufacturers can make their own non-standard extensions and benefit from existing work.