Look at Tour rider's power files. On the flats and in the peloton when there are not attacks, they are doing relatively low RPM and low power. Of course low for them might be 250 watts and in the 70's. When there are breaks and it gets strung out, everyone's cadence increases. I'm not going to dredge up the power files, the reason they cut RPM at lower power is very obvious.
This guy would be a Bikeforum C- rider since he averaged only 78 RPM. 26.7 mph.
For 24 straight hours. Christoph Strasser average power was only 265 watts in this race, I have seen him do higher. Marko Baloh will be in the 70's too.
https://www.strava.com/activities/5653170343