I actually can see both sides of this argument. I’m a marine scientist who has worked in fisheries management and fisheries policy for almost a decade. At a population level, I do think the evidence is there that taking ornamental fish out of the wild isn’t impacting the species as a whole.
What I do think is interesting though is that at the end of the day our hobby is one of animal husbandry. And when it comes to yellow tangs, the captive bred tangs are a hands down winner on the animal husbandry front. Sure, they may not be cheap, but at the end of the day they’re more likely to eat, survive, and thrive in a tank than wild caught fish.
I think all of us here on this particular forum are the best type of reef keepers because we are taking our time to do research and read up on our choices, but there a lot of people who keep fish that aren’t like us. We can’t ignore that a lot of those wild caught fish die in the process of being shipped, held at stores, or being sold to someone who doesn’t know how best to acclimate them.
I, personally, would love to see a lot more investment in and demand for captive bred fish because I think it’s best for what is at the core of this hobby - our love for fish and desire to keep them healthy and happy.