Whether you build an antenna on your own, install a prebuilt antenna, or have someone else build it, grounding is a critical part of installation.
Offering advice to not ground outside antennas is irresponsible, contrary to all known laws of physics, civil law, and city codes pertaining to static charge buildup, and downright criminal!
There are three types of grounds. In order of difficulty to achieve, they are (from most difficult to least difficult):
The methods and practices used to achieve each of these are different. Static grounding is the most difficult to do with guaranteed results, while electrical grounding is easy and can be considered to work perfectly in most cases. RF and electrical grounding are not important for static discharge (lightning) safety, so I’ve left them out with regard to outdoor antennas.