Sure, designing modern integrated circuits isn't easy. However it still is way easier than what you need to manufacture them. Design of digital integrated circuits is commonly more understood with information being readily available.
In theory you could gain the knowledge to design an early 1990s CPU at the logic gate level by reading some books and doing a bit of research, on the other hand actually manufacturing such IC would take considerably more effort.
In theory you could gain the knowledge to design an early 1990s CPU at the logic gate level by reading some books and doing a bit of research, on the other hand actually manufacturing such IC would take considerably more effort.