Actually ARM SOC faces some serious issues about increasing performance. Especially with memory on chip. None of the ARM fabs are able to produce at the size needed to get further speed increases easily. Intel on the other hand is still driving their size down.

Most of the performance increases in ARM recently have been from multiple cores. That ship has sailed. The low hanging fruit has been gathered. Anyone expecting performance increases similar to what Intel managed on the x86 over time is going to be disappointed.

Intel will probably get isn't offerings down to compete with ARM before ARM is able to boost performance to compete with Intel.