5G is an umbrella for different types and technologies, and I believe that’s the confusion part of what the artice mentioned and the reader views. 5G has three main categories (technically two but separating the 2nd one to further explain it), 5G NSA (non stand alone), where the 5G RAN uses an existing 4G LTE core, 5G SA (stand alone), as the name implies, is stand alone from previous generations and has its own architecture and core, new radio, etc., and the third one -which is still a SA by the way- is the mmwave, what the article is referring.

This article has a thorough explanation (1)

In most nowadays 5G implementation is the first one, where you get a slight enhanced LTE, as it’s easier to implement, SA, which provide extra features is still not widely used -although it’s changing, and then you have the least adopted one is the mmwave due to its new bands (unlike the sub-6GHz) that require new radio/towers/etc. on a higher frequencies (also higher noise), and also new UE (or user equipment/device), which so far only very limited devices support that. In Canada, we did some cell surveys utilizing robots/drones to map the areas at different altitudes to find the deadzones and coverage, and you can say in most of the results, NSA can have the coverage as the LTE, mmwave in some cases we had not just to maintain a clear line of sight to get any signal, but also we have to be relatively close. So mmwave adoption might still in its early stages, it’s also why so operators went with C-band instead.

(1) https://dgtlinfra.com/5g-standalone-sa/#:~:text=What%20is%20....