A classic example of this is the Australian government that made Gambusia a noxious species. They said they would eradicate the fish. That was 20 years ago and to date they have no idea how they are going to deal with them. If they hadn't made them a noxious species, then collectors like me could still be harvesting thousands of them from the creeks every week to sell to shops as live feeder fish. Instead, we're not allowed to touch them and the government isn't touching them, and they are breeding like flies and decimating the native fish stocks.
As for Bangaii cardinalfish (and all cardinalfish), they are so easy to breed and rear up, I'm amazed they are even wild caught. They literally breed every month. The males incubate the eggs and young in a buccal pouch, and the babies can eat newly hatched brineshrimp as soon as they start swimming around. They are as easy to breed as livebearers. Having said that, considering the planet is warming up and the oceans are getting hotter, the CO2 levels are increasing at a rapid rate now, and the phytoplankton is about to die, what difference does it make when some wild caught fish are brought into captivity. We're all screwed anyway.