I think the instruction set is basically irrelevant to the discussion. Intel is losing to TSMC at the actual foundry process. Intel is losing to AMD at the design of desktop/server class chips running the x86 instruction set.
Within the ARM world, Apple is running circles around the competition. Qualcomm can’t compete on mobile SoCs, and Samsung’s Exynos is even worse. Qualcomm is trying to get into laptops, but the performance and efficiency aren’t competitive with Apple, and might not even be that far ahead of AMD.
Intel is betting the company on various stacking and packaging technologies to fit way more stuff into a small surface area, but basically is left hoping that this works.