The competition in these types of group rides is usually self inflicted. Most often small groups meet regularly and informally to ride together. Riding in groups is always a great opportunity to learn and improve your riding skills. These are usually supported tours, meaning there is a van behind you somewhere, carrying your stuff and helping with breakdowns. The downside of road riding is the obvious risk involved sharing overcrowded roads with cars and trucks.
Savvy riders choose their roads and the times they ride to reduce the risks.
Riders are easy targets for drivers who experience road rage or who are simply hateful or mean-spirited. Graceful and defensive riding can significantly reduce the hazards and negative encounters with vehicles, but three young guys in a pickup truck is almost never a good thing. Many riders only ride off-road on mountain bikes or hybrids bikes to avoid highway hazards. You can bicycle without ever being on the pavement. Fat tire bikes have definitely become more popular than road bikes.