Pro: each wavelength has greater amplitude ("height"), so each wave can carry more data (and thus, more detail) in each complete cycle.
Con: as a wave gets taller and taller, it has less and less penetration... through trees, fog, buildings, glass, the metal of vehicle bodies, etc.
For those old enough to recall the early cordless phones in our homes, a person could carry their cordless all over the house and even the neighborhood.
As phone technology improved the sound quality by using higher frequencies, the cordless house phone needed to be inside only, and eventually, it often needed to be in the same room or have a clear Line of Sight (LoS) between the handset and the phone base.
That led to systems with multiple extra phone bases, although it was marketed to that public in a far different manner.
For rural folks, already suffering with little to no 4G or 4G LTE cell signal, even when living within 2 miles of multiple cell towers, which often play hot-potato with cell phones as the received signal strengths vary... the Grand 5G Service will be nothing short of a horrendous nightmare.
With even less penetration, rural customers who are looking forward to this monumental advancement, should be papered for disappointment and the sound of crickets rather than the latest YouTube.
If they do have any signal, then the advancement of the software coding, required to process the high speed/high volume of data will make their phones off little use, as varying signal strength will lead to too much lost data at 5G, and quite possibly zero-tolerance for the typical 3G signal that remains most prevalent and reliable in many geographically challenged rural areas.