It's undoubtedly true a fair few people don't know how to use them properly. It amuses me if I'm the last one to arrive at a three way roundabout only to find vehicles at the other two junctions, just sitting there. So then we're all just sitting there playing a game of 'who's going to move first?' Sometimes it's even more amusing if you start to move and one of the other vehicles takes that as their cue to start moving!Nobody seems to be affected by people in wrong lanes at roundabouts.
Causes lots of issues, albeit smaller maybe
Or vehicles going straight on who don't go around the roundabout properly, meaning if you're going right you have to hold back. Another common one.
However when roundabouts are used by excellent drivers like me, they work well