Nope, the RTX 30 series uses DP 1.4That's a good point and the only reason why I skipped multiple monitoring configurations is that it's not something that's usually associated with high refresh rate gaming. Of course, with new monitors typically supporting high refresh rates and motorsport/flight sim rigs often containing two or three monitors, it's valid that it should be in the article. I'll add it as soon as I can.
What graphics card and monitor do you have? As noted in the article, some monitors only support their advertised refresh rate using DP.
GeForce RTX 30 series has DP 2.0 and HDMI 2.1, so there's no reason for the 40 series to not have DP 2.0 - it's monitors that don't have it.
I just confirmed that on my own 3080 12gb and the newest 3090 Ti from both Asus and EVGA.