The difference is that you need an x86 license to produce a processor that uses the same instruction set. IIRC there are just three companies that are licensed

The difference is that you need an x86 license to produce a processor that uses the same instruction set. IIRC there are just three companies that are licensed - Intel, AMD and possibly VIA if they're still around. It's not just the implementation that's patented. Whether or not RISC-V implementations become encumbered by patents, at least it is now possible for companies to make their own processors without having to create the entire ecosystem too.