Be that as it may, it doesn't mean that they aren't competing in a Cycling sport. And being such a large majority of the competitors in Cycling sports, having no need for pack skills in their sport, it follows that pack riding is not an essential part of cycling, nor even in the sport of cycling.

There are a lot of reasons for pack skills and pace lines. But IMO "You're not a Cyclist unless you ride in packs" and "You don't know anything about the Sport of Cycling unless you pace line" are not among them.