That is incorrect. If a electromagnetic wave can penetrate stuff is not a linear function. E.g. visible light can not penetrate through a body but higher frequency such as x-rays can, however in the microwave spectrum it's different. Somebody said that short waves are really low frequency and can therefore go around the world, however they can really only do that because they cannot penetrate the ionosphere and are reflected back. In certain parts of the EM spectrum you can make certain assumption.

It's actually the opposite. Shortwave (3-30Mhz) goes around the world whereas a high frequency such as 5G (5Ghz) cell data you have to have a node on every light pole.

Shortwave is 100 to 10 meters wavelength compared to 5G which has wavelengths measured in millimeters.

A radio station emitting long waves can be heard almost anywhere on earth. With poor quality, of course. I used to listen to radio stations at 20 000 km away for fun.

With a decent enough antenna setup, the quality isn't poor. I've had stations come in super clear from eastern europe while I was sitting in southwest Wisconsin using an antenna that was just a bunch of speaker wire thrown up into a tree.

5 and 6 should be similar in terms of range at same power levels. BUT, 6 GHz will have lower transmit power than 5 GHz until database aspect of 6 GHz is built. Still great though..

That's definitely incorrect.