I think he is a little overrated, and the only reason he is that much known is because it is actually rare to see former Intel engineers opening a Youtube channel with some Intel content. His take about how to fix Spectre made completely no sense to me, so either I missed something, or he is actually lacking on some technical subjects...
Anyway still some interesting insight about what he saw happened there.
The situation can be explained in a very boring way in any case. You had the tick-tock cycle, then Intel 10nm was broken, but they thought not anything they could not fix with one more year of process debugging, maybe 2 worst case. And they had so much advance that they could even have tolerated 3. Except 10nm basically never worked. And the new microarchitectures were designed for it... They switched to thinking what to do with 14+++++++++ far too late, and even then I admit the result is suboptimal.
SemiAccurate is... let's say very very opiniated (as usual), to be polite, and I don't think Rocket Lake will be that much a disaster, but also yes Zen 3 is solid, although not that much magical and a bit overpriced for now (but I'm sure AMD will be able to adjust if really needed)
The final thing is: Intel had really an insane advance, and medium/high core count is not that much required right now in volume for consumers. I'm not sure about the situation in datacenters, could be more of a problem for Intel. But Intel has a level of market addressing that is insane and far above AMD. So it is not that much a big deal for Intel, at least if they manage to come back on tracks in the coming years.
So did Intel became that much uncompetitive? I don't really think so. Enthusiasts are just so a bit too much now that AMD really is competitive. Choosing Zen 2 was still a (often excellent) compromise. Choosing Zen 3 over Intel would be a no-brainer if cheaper (and when you can!), and depending of what you do it can often be the good choice even at the current prices, or at least for some specific models.