You can mess roundabouts, but it requires a sever lack of competence that we rarely see TBH, and it can be progressively improved (signage, better visibility, lines etc)

I'm with you on how some will still be dangerous, and can require traffic stops. But it's still better than going back to a plain stops IMHO, and it's usually in portions where it was already dangerous before putting in the roundabout. In practice I've never seen a reversal of a roundabout to get back to a plain intersection.