Agreed on everything except the road racers. Maybe some want discs but the pros don't. Discs are more likely to rub for them because pro cyclists generate enough power to twist the wheel. If you are trying to gain seconds over a few hours then the sound of rubbing must be torture. Chris Froome spoke out about it recently. Team Ineos just won the Giro and they don't use rim brakes because their sponsor does not oblige them to. It looks like the reason pro racers have discs is because the bike industry makes them. This is so that they can sell new bikes to people who already have a perfectly good one. It makes no sense for pro riders to have disc brakes. Their high end rim brakes are looked after by mechanics, they are lighter, they don't rub, wheel changes are easier and pros don't do a lot of braking anyway.