A72 is a mobile chip, so still not particularly relevant to tuna-fish's claim about high end servers. The raspberry pi 4 is not a high end server.
> half the die area
Much of this is free when comparing a 16nm design to a 7nm design. See footnote 1 in your link.
EDIT: I was curious, so I looked up the transistor density of tsmc 16nm vs 7nm.
16nm: 28.8 MTr/mm^2
7nm: 96.5 MTr/mm^2
So I think that sifive core with "half the area" is actually not quite as good as a die shrink of the A72.
So is Apple A13. And yet it's been reported to outperform all Intel desktop CPUs in single core performance (I find the benchmark dubious, but I do believe it's close, and faster than it has any right to be given the super low power consumption). The only reason it doesn't do so in multicore perf is the limited TDP - a concern which does not exist in high end chips.
https://www.sifive.com/blog/incredibly-scalable-high-perform...