To be fair, there are absolutely situations where the court should be able to say "This particular trial was a shitshow and we're throwing it out, but there should still be a trial." Say, if the defendant has a malicious or incompetent defense attorney, it's fair that both they don't have to suffer the harm of that being their final chance to defend themselves but also the government doesn't have to just fully acquit them forever because their counsel sucked. Either alternative would lead to some pretty absurd incentives.