I can't talk about group touring because I've always gone solo (cross-continent). If you can't stand to be with yourself, you may have a problem! On a lot of trips you will encounter many other cyclists that you can relate to (or not if you prefer) - I've never hooked up with one another for more than a few hours. Inevitably differences in preferences (I'm usually slower!) bring a parting. Riding is one thing, but camping is another - I tend to share campsites quite frequently.

One advantage of sharing a tour is that some main items can be limited to one and the load shared ....ie: tent, stove, pots. Also an important aspect of having a partner that I envy is getting the added encouragement from another. Sometimes it's very difficult to conjure up incentive from a tired inner self - but another person's very presence can be a motivation in itself. And no one likes to appear weak in someone else's eyes. I do some training rides with a friend who is a better cyclist than me, and I find I push myself more just to prove to him I'm better than I actually think I am.