Maybe in a few select benchmark at the cost of almost double the power.Not at all, just providing accurate information rather than misinformation. I'd advise to look at a few real tests online (other than gaming) you'd see Intel is still performing better with four year old architecture.
I notice you don't mention anything about the crazy power consumption of comet lake.
You think the vaunted Comet Lake i9 pushing 250 watts will work well in an iMac chassis? Intel is behaving the way they were when the P4 was at its limit and couldn't compete with AMD so they came out with ridiculous chips like the P4 Emergency Edition that consumed crazy amounts of power and heat.