When I’m cycling I get much more annoyed by other cyclists or pedestrians that I do with car drivers. Contrary to expectations there seems a higher percentage of careless idiots in the bike/foot camp than the driving camp. Cyclists, on average, appear much more selfish than drivers, as if they’re the only person on the road.
One variation on the “speedy off the blocks, but terrible sprinters” cyclists is those who arrive at a red light and work their way to the front of the gaggle of cyclists, often way out past the lights themselves. And then when the lights change they wobble away slowly and everyone has to overtake them yet again while all the cars are also trying to overtake them.
I guess they’re doing it because they feel safer out in front on their own but it makes life more dangerous for everyone else. Unlike the other idiots these seem as likely to be women as men.