I agree it will take awhile to completely take over even the low end market, but like there is already a data center running on RISC-V that was in the news cycle a month or two back. Intel has been putting a lot of money into it too because they know the change is coming. We are on the edge of a major shift needed for AI anyways. I think that will be the death knell for x86. The memory and cache bus structures need to change to accommodate tensor math much more efficiently. Why restructure the dying x86 so substantially when it could be done in RISC-V and make most hardware antiquated at the same time to finance the bleeding edge shift. I think The big players will still be on top, except ARM will fade into irrelevance like MIPS. Proprietary/planned obsolescence/exploitation in the digital landscape is a major problem that needs to go away. All the relevant companies have access to reverse engineered hardware from their competitors. Proprietary only exists to exploit end users. RISC-V is a small step in the right direction of restoring the right to fundamental ownership.

Id say more like 20-40 years. x86 won't die that easily