"5G signals cannot magically travel vast distances. In fact, they can only go relatively short distances and struggles to penetrate into buildings and through walls"
This depends upon the frequency bands used for any particular 5G deployment. In the UK, I believe bands around 3.4GHz to 3.8GHz are to be used, which should mean that 5G signals here have similar coverage and penetration into buildings as existing mobile networks. The so-called "mmWave" frequency bands that make possible the highest data rates are the ones that do not have the range and penetration.