Sounds like your fan curve is much lower rpm than what I setup.
My basic fan curve is based on rpm to temp and always 500rpm or more. Percentage is only used to get desired rpm. Something similar to below. Actual settings vary depending on fan oscillation to RPM, want quieter performance, etc. I ant CPU to stay below about 80c. I can't say it makes a difference, but I have systems like i7 920 @ 3.8GHz that's been in use for at least 10 years now and still going strong. Like I said, I don't now how much if any difference keeping everything below 80c is part of reason why, but I like to think it is.
My fan curves are similar to below:
500-550rpm idle
650-700rpm @ 45c
850-900rpm @ 55c
1050-1100rpm @ 65c
1200-1300+rpm @ 70c
Full speed @ 75-80c
I setup my fan curves to keep system below 80c so fans hit 100% at 75-80c so system never gets any hotter than that.
What are fan speeds and temps at idle, like when just surfing web?
Changing cooler won't make things cooler unless you increase fan speeds to supply case with more cool air and are moving more of that cool air through coolers.
I don't think there is really a lot of difference between AMD and Intel dies / die placement under IHS and/or flatness / convex / concave of IHS and cooler base on AMD with normal size IHS. But we do need to keep in mind they do have bigger chips under them than older CPUs did. The big difference is Threadripper with it's credit card size IHS with huge chips under it.