I've openly mocked 5G on Twitter; phone companies have been pushing this to get people into new phones and new plans. But it's predictably not awesome. I expected it to be better than 4G LTE, but it's consistently worse.
In this particular random test (from my office in downtown Fort Lauderdale), 5G is significantly worse.
I've done other tests with similar results. In fact 5G is so bad that I've turned it off. The default setting for the iPhone 12 is 5G Auto; which means use 5g when you have a strong signal. Selecting 5G will always try to connect to 5G; a weak signal will drain your battery faster.
And despite the coverage maps which show stellar coverage in Fort Lauderdale, my phone was on LTE most of the time when I had no WiFi. So the signals are spotty; like the old days with 3G.
The truth is that 5G isn't worth it. I suggest you turn it off altogether.
How To Disable 5G on your Iphone
Settings -> Cellular -> Cellular Data Options -> Voice & Data
And Select LTE
Someday, 5G will be the way to go. But they need to deploy 100 million more antennas before it delivers the hype. For now, it's just a marketing gimmick to sell phones and contracts.