It's Intel's vertical integration that has hamstrung its chip design for about half a decade. 10nm transition was an unmitigated disaster and because of it Intel has haemorrhaged technical dominance and has only really maintained market dominance due to entrenched and slow moving decision cycles within the data centre space and to a lesser extend the consumer market.
Intel will likely stablise over time but they won't enjoy the market dominance they had for most of the last decade.