I was shocked how good and clean my homegrown fish taste. They're consistently better than wild caught, and vastly better than the nasty stuff you get at most restaurants and grocery stores, most likely due to mine being reared in a cleaner environment and having a better diet.
Regarding their environment, my fish live in naturalistic, fully functioning ecosystems as opposed to warehouse factory tanks. They get to frolic, play, explore, enjoy the sunshine, grow up, and mate. Some get to grow old. They lead good lives and seem happy.
Regarding their diet, I grow tilapia that prefer to be primarily vegetarian the older they get, and I cater to their preferences. Fish accumulate good Omega 3 fatty acids by eating plants or eating other fish that eat plants, so my fish get a diet of something like 70% plants/algae, 10% worms, and 20% commercial feed. That way the bulk of their nutrition comes from where it should, but they still get the benefit of having a well-balanced feed as a nutritional supplement. My fish are in my garden, so I'm constantly throwing lettuce/spinach/etc into the water for them to eat, sometimes even treating them with big stuff like pumpkins. Factory farms that raise their fish entirely on commercial feed create fish that are somewhat unhealthy to consume, since instead of piling up good Omega 3 fatty acids, they accumulate high levels of bad Omega 6 fatty acids. The ratio of bad versus good fatty acids in factory farmed tilapia can be comparable to that of bacon, but fish raised on a more natural diet don't have that problem, so it's important to be aware of where particular fish were farmed and what they were fed in order to have a good sense of how healthy they are to eat (and how tasty they'll probably be).