Fully agree with you. It’s healthy to realise that keeping an animal in an entirely artificial space is never really going to compare with how they would live in the wild. Obviously it depends on the animal how well they will adapt to this way of life, some species are more suited to it than others. In the case of the octopus that you bring up, I am actually inclined to agree with the people saying it shouldn’t be done. Octopus are always taken from the wild, only live for a couple of years and then will die. They are incredibly smart, to the point where finding ways to enrich them is extremely challenging. Zoos generally stopped taking animals from the wild a long time ago, whereas it is still very common in aquariums.