I never said anything about AMD. The fact is that the high end AMD chip (3950x) requires LESS cooling than this 10900k chip. And the HSF that comes with the AMD 3900x does fine, and thats actually the competitor of the 10900k.
Edit: Sorry, I reread your first post. I edited the reply.
All of this is correct.
The stock Wraith Prism can actually get very close to 90C with the 3900X, but let's be fair, it's FREE vs absolutely nothing with the Intel series. And I'm fairly sure a HSF like the Prism would get completely overwhelmed by a 10900K. That would make for a really interesting video come to think of it, creating a mount and testing that just to show how it would perform.
The thing is that the 3900X doesn't normally sit in the high 80s in general use, only with all core loads like blender, and it's operating normally and not too wild. Increasing cooling for it only nets about a 1% performance uplift (when I had mine I used a Noctua 140mm DH and it stayed under 60C in daily use @ 4.2Ghz!). Thus, the included HSF is a great value add for the 3900X, which outperforms the 10900K in almost all non gaming tasks stock/PBO v OC, at a fraction of the heat output and power consumption, and with the 10900K needing at least a $80-$100+ HSF to function respectably.
Relevant :
https://www.techspot.com/review/1875-ryzen-3900x-wraith-prism-rgb-vs-liquid-cooler/
I could have used the stock HSF for the 3900X and not really lost anything, but I was caught up in the Zen2 launch hype and wanted to see how it fared with high end air. And, it did great, very quiet etc. I ended up downgrading it because the 3700X I initially had was basically identical in gaming and I personally don't have a use for 24 threads.
Where I think the Ryzens get it slightly cheap are the recent stock HSFs for the 3600, 3300X, etc. The Wraith "Stealth" is only marginally less trash than the Intel stock coolers, but I don't find them very good at all. The Wraith Spire for the 3600X is a lot better, and I'd call it marginal and not something you have to run out and worry about replacing unless you just really hate noise AND you run frequent all core loads. In general use they're fairly quiet, but load up anything demanding and they have to ramp up to keep up. The Prism for the 3700X and up, well, it's fine of course, and that's a lot better deal than nothing at all like Intel K.
Of course, Intel copied K series idea with the XT not including HSFs lol. Complete WITH a price hike. Goes to show that at the end of the day every company is in this to make money. 😅