In fact, I think if you're a rider on a group ride who constantly drops the group somehow when on your roadie/race bike.......start bringing the slack geometry slow tire bike for a better workout and maybe better tactics. You ride differently when you're able to just attack and disappear versus having to in-fight and conserve/burn.
It's fun once or twice to drop the group up all the hills, but after a while you're just doing intervals alone. It's more fun being "in the mix".
It sounds like a "flex", but it's a valid point to intentionally handicap yourself on a group ride to make it interesting. Nobody is winning anything. Strava PR's or KOMs don't win races or get you a PR in a time trial.