You’re basically saying that just because we haven’t been great at general fishery management yet doesn’t mean we won’t get it right next time. But the problem

You’re basically saying that just because we haven’t been great at general fishery management yet doesn’t mean we won’t get it right next time. But the problem here is that fisheries are literally the textbook example of the tragedy of the commons and there will always be someone looking to capture the benefits while externalizing the costs. I’m not disagreeing with you that unsustainable eating is the root of this (and many other) problem but the only successful solutions has been extremely strong semi-militaristic (eg Coast Guard with teeth) enforcement of fishing quotas that are quite unpopular for all involved: fishers who lose jobs, eaters who lose access to a favorite taste, etc. No one likes taking their vitamins as it were.