Which OS is that on? Mine was on Linux, perhaps that makes a difference. Also I have a rather crappy cpu (i5-8250U); for you I still see the gaps even if they're smaller (both in absolute terms but if I'm seeing it correctly also in proportion to network loading time), so perhaps a faster cpu helps as well.

I have FF 91 on Linux and mine takes ~200ms: https://i.imgur.com/EzdLYXb.jpg

This is with uBlock, HTTPs Everywhere, "I don't care about Cookies", Greasemonkey, etc etc

I have a 1700x, so a bit faster than your 8250U, but released the same year.