It won't. Due to its licensing, x86 does not stand a chance against RISC-V.
Especially not after Apple, Microsoft and others (e.g. Box64) have demonstrated ability to run x86 code elsewhere reasonably well, thus providing a clear migration path.
These actions by AMD and Intel are seen as a desperate attempt to keep x86-64 relevant. As non-x86 hardware increasingly shows up and runs legacy code with little issue, x86 is doomed.
I will wait for x86's doom, but it will take patience. After all, people have been saying it's dying and will be replaced by some RISC alternative for over 30 years now.
Can you cite any sources for this? What makes you say this? Can you cite one (1) example?
I ask because it is entirely inconsistent with my experience with the available SoCs and their boards. They all implement the specs that were available at the time of design. Sometimes drafts out of necessity. And all of them use OpenSBI as their machine mode firmware.
This is false to the point it reads like FUD to me; It couldn't be further detached from reality.