arnsider wrote:In answer to the OP, the average speed is so subjective as to be infinitely variable and not really relevant outside of competition.
Or when touring, and trying to work out if you have time to reach a campsite. Or cycling to a meeting, or to catch a train, or to any other appointment. Or when joining a group ride, and wanting to know in advance whether you'll be comfortable at the kind of speeds that the others enjoy. Or for working out whether the training you are putting in for next year's grand tour is having any benefit.
In fact, it's very useful to know your average speed for any number of reasons, whether or not you have interest in either increasing it, or comparing it to others.
I'm a trendy consumer. Just look at my XT1039 using hovercraft full of eels.