There’s zero demand for products that are hiding safety issues that nobody was seeking out (e.g., toys with lead paint, batteries that explode)
Demand for illegal things isn’t in a vacuum. It’s hard to enact prohibition on alcohol or cannabis (extremely easy to produce) versus prohibiting something more complicated to make, difficult to smuggle, or less desirable to buy.
If my government bans Crocs am I going to go through the engineering effort to make them myself? Plus, if I go outside the cops will see my illegal Crocs very quickly. I have plenty of alternatives to Crocs and most of them are better. Most likely, I won’t even think about the ban.
We have a good example with incandescent light bulbs. I don’t know anyone who has attempted to violate the ban on home incandescent light bulbs.
The whole “everything should be legal anyway because there will always be a black market” philosophy is not a universal truth and we need to stop assuming that it makes sense.