“New Intel chips were often delayed and offered only small improvements over previous generations.” As noted on HN and elsewhere, Intel’s struggle has been in manufacturing. They minimized risk (“got lazy”) when Moore’s Law reigned and their fabs were 1-2 generations ahead of everyone else, but have since squeezed every last architectural drop out of 14nm. Put Tiger Lake on TSMC 5nm and a lot of M1’s lead goes away.…
The other key point is that Apple can pick and mix from the technologies they use - they've unbundled Intel - choosing the best that they can find for their needs whether in-house or externally.