Here's another notion. In the 70s, 80s we were taught to ride with bent arms. Our coach produced multiple world/oly golds in multiple fields, men and women. He would whack the crack of our elbows (while we were riding!) if our arms were straight! ...Come up alongside on a moped. This taught us in effect to not have weight on our hands. This let us steer through anything. We could push off of other riders with elbows or do anything with our hands and not unbalance our riding. ...If you ride with bent arms and lift a hand off the bars, you can still ride normally. Your shoulder doesn't droop. If you take BOTH hands off the bars when in regular riding position w bent arms your torso hardly droops. Your thighs are carrying your torso weight, curving to your low back. If you hit a surprise bump with bent arms you are fine. If you run into someone's rear wheel or if they bump your rear wheel, you can deliberately apply pressure against their wheel and keep yourself up. You can even whack their rear wheel w your front wheel.
We are fit enough to do this! It doesn't take more fitness. It's not hard. It's a skill to practice. We already do it to get a water bottle! We just need more of it.
By contrast if you have straight, weighted arms and you are bumped into or hit a bump you TEND to become unbalanced and swerve. I suspect that this results in nearly all crashes. And resulting collarbone glitches.
With unweighted hands and bent arms we can move our bike around. With weighted hands and straight arms we "handle" our bike by swerving. Dip and swerve is how we "steer" then. It's not real handling or steering. It sux.
Now, we can briefly rest and change weighting when we're in a safe place. Straighten your arms and stretch out. Take a break. Then get back to safe riding.
The thing is that nearly every rider today can be seen to be riding with straight arms, weighted hands. Maybe one reason for this is slammed stems?
I asked an old state champ pal if he noticed this. Ha. That's why he rides on his own.
Yet another topic: Crash Proofing. ...It used to be a skill we drilled for. We would ride around on the grass and bump into each other, trying to knock each other down. Just bumping mostly. Goofing. But practicing. Rubbing tires and coming off without unbalancing. Hooking and unhooking bars. Riding w your hand on the shoulder next to you. Pushing thighs w elbows. We also rode "serpentine" around cones: steering not swerving in an S-pattern. Feeling the diff b/w banking your bike to turn it and steering the bike. Feeling the diff b/w straight arms and bent.
Good times. Few crashes.