Wouldn't it be more convenient to only need one wifi network without 2 frequencies? Especially in dense urban areas where "wifi pollution" is high and it can be difficult to find an unused 2.4GHz channel

I usually disable 2.4 Ghz WiFi on the routers I set up because 2.4 Ghz WiFi is just a needless radio spectrum pollution nowadays (unless you need to connect retro devices). I initially decided to phase it out in hope of improving BlueTooth (wireless earphones) stability.

2.4Ghz covers more area.

Yeah, and because of that it quickly becomes useless in an apartment building surrounded by a few hundred 2.4GHz access points.

I hope one day people will start integrating grounded shielding into apartments walls so in every separate apartment there would only be local wifi signal and nothing else. As a bonus that would probably save us from computers extinction once the Carrington Event (powerful solar EMP) repeats.

As I said, it's slightly annoying, not a deal-breaker. It required me to change my wifi setup to be dual band (I'm in an apartment so lots of congestion on 2.4 ghz, and I don't need the extra range).

Maybe their AP only supports that?