Intel has slacked hard since the 2000-series. One shitty 4 core release after another, until AMD kicked things into gear with Ryzen.

And during that time you couldn’t buy Intel due to security flaws (Meltdown, Spectre, …).

Even now they are slacking, just look at the power consumption. The way they currently produce CPUs isn’t sustainable (AMD pays way less per chip with the chiplet design and is far more flexible).