It was definitely manufacturing troubles bud. You can see it in the way they first "launched" 10nm chips as supremely supply limited tiny low power mobile parts and the fact they had to backport their 10nm to 14nm. You don't do that for fun and you don't do that while your competitor is nipping at your heels.I would not be surprised that Intel would still be on 14nm. Make up some BS explanation why they are still there when Apple has iPhone 2nm chips in 2024.
Intel stayed at 14nm to save on manufacturing cost. From 2006-2020 they had all PC OEMs as customers. Where the incentive to improve when you have a monopoly? Shareholders will be happy as their dividend will go up and Intel management gets their bonuses.
Apple's quarter million iPhone chip orders to TSMC is the only reason why M1 chips were possible. AMD/Intel ships a quarter million PC chips annually at time when Apple was still using Intel chips.
Intel is in danger of being rendered impotent if Windows 11 on ARM gets momentum. Imagine 2nd best chips to iPhone on a Windows machine?
Only reason why you'd go x86 is because of the legacy software. Give it a decade after new Windows machines are 80% ARM and Intel become a shadow of its former self.
They definitely did rest on their laurels a bit while AMD was down which is why consumers were stuck on 4 cores max for so long but they definitely had 10nm manufacturing troubles.