Roundabouts still work really well. Where I used to live in the Midwest, we had lots of them. I have zero issues getting through Kelly Square now, even when people speed through the roundabout or there's an overly cautious person in front of me.

Just let the speeders go through before you attempt, cause the point of the roundabout is to go when you have space and time. And let the cautious people take their time as again, the point of the roundabout is to go when you have space and time.

As for the hazards, that happens in all places, not just roundabouts, so to me that's a moot point.

I think your issue is with masshole drivers, not the roundabout.