Is aquarium life good for animals?

So for background I come from a family of custom aquarium manufacturers focusing on the most natural methods of aquaria care and maintenance.

The answer to your question is that it depends on a multitude of variables. Each species has its own unique care requirements that it really falls onto a species to species comparison. I've kept most freshwater fish thriving using nothing but planted tanks. No filters needed and IMO they do the best in that sort of setup. Marine is trickier, but I utilize bacteria and natural filters only and always seem to have better results.

The thing I always say is research the species, and keep it as close to nature as possible. There is a reason no one is able to care for a great white shark in captivity. Their care is so unknown and we are not able to keep the tank parameters perfect for them. Most fish and aquarium life however are relatively easy to care for as long as proper care, attention, and research is taken.

Some animals in my opinion should not be in captivity. Orca's are probably my best example. They are highly intelligent, social beings in which we do not have the proper means to care for them in the best of situations. However, their presence does have a positive effect on orca wildlife overall. The same advice can be said about non-aquatic wildlife as well.

In many cases of large, intelligent or social creatures the care is not perfect. Many charismatic megafauna in zoos are constrained in sub-optimal (read: not abusive) enclosures and care. However, the greater good is important here. While some tigers, for example, are kept in captivity their presence allows for us to keep the ones in the wild via raising money for conservation funds. While abuse, physical or mental, is never okay some costs will inevitably be had from keeping an animal in captivity.

So sorry, if this wasn't the direct yes or no you hoped for, but there are dozens upon dozens of different ways to view this answer. For the TL;DR version I would say it has the potential to be great, it has the potential to be bad, and it has the potential to be decent enough for the animal to not suffer. Its up to caretakers to decide how they want to keep the animal in question.

IMO the answer will be neither yes nor no. It all depends on the person who is taking care of it. Usually aquarium fishes thrive in an atmosphere closer to there natural habitat. It can be provided in a small tank. I have aquariums since childhood and I have seen them very happy when the proper environment is provided with a lots of plants and care.

Even though taking care of the freshwater aquarium fishes are comparatively easy than marine fishes as providing the natural atmosphere for them is very challenging and it is not only fishes it is about any animals. So till the time you are able to take care of them as per their requirements it is good however if you are not careful or do not do proper research about their habitats and nature it is going to be bad.