How to overtake motorcycle columns properly?

Hello, here’s a topic that some people will find provocative from the ground up, but it’s not my intention. Just want to know how you would do it “right”. So this is the following: Last Sunday I went to the sport, that’s about 35km of road with many long straights. After about 10 km I had a group of 5 motorcyclists in front of me, who drove so about 80 km/h. Most were allowed 100 km/h. In front of the group also a car driving the same pace. he got the impression, he stopped the motorcycles, but the motorcycle group did not overtake. Since I had not quite so much time, I wanted to pass. 5 motorcycles & 1 car to overtake was not in it, that did not give the view. Since the mopeds also did not keep the necessary safety distance between each other, I could not overtake them individually. After a roundabout the last motorcycle lost the connection to the group, the distance to the rest of the group was about 60m So I started overtaking. Then, when I was next to the moped, the driver gave up gas, pulled past me to the right again and closed with full throttle to the group, then to go back fully into the irons so that he didn’t shoot off his front man. While he braked, front (about 500m away) oncoming traffic appeared, so I broke off my overtaking maneuver. Since the distance between us didn’t get very large (my car goes quite well), I also had to brake quite hard, not to hit it. My question: How should you overtake slow (cruising) motorcycle groups if you are not left in between? As a driver, “fast” motorcycles are always expected to take consideration and leave room, but if you want to pass as a driver, it is not tolerated. Is it such a taboo to overtake a bicycle with a car? Or do you have to do this soon in the overtaking ban, since one-lane vehicles can be overtaken? Finally: I have nothing against s Chnelle or slow bikers, I’m one of them myself. But why is it so bad to let a car pass?