Legislation is the way to go for fish health. First, legislate that every fish store provide free of charge a pamphlet of basic aquarium principles. Second, every fish bought must be accompanied with a species specific care sheet prior to purchase and signed buyer copy retained by the store. Third, prior to any fish purchase, the buyer should pass a basic aquarium exam. Fourth, legislate fish anti-cruelty statutes.
The place to start is in writing our legislators. I am not for the "nanny state" telling me I can only have a soda in a small cup, but I am against current unethical LFS practices and misinformation. And, I think goldfish suffer worse than bettas on that.
I bet everyone in this forum would be thrilled to get a personalized care sheet for each of their fish and quite happy to take a basic aquatic test.