Aquariums won't go away any time soon, and I prefer them. Most fish don't care or can't tell their in captivity. I've seen a few were their otter exhibits seem questionable, but most have enough space. Very few aquariums have dolphins and whales and these animals really shouldn't be in such small spaces.

You can still see dolphins and whales, it just takes more effort. The ferry between the North and South island in New Zealand is often followed by bottle nose dolphins. There are tour groups in Seattle that take people into the sound to track down Orcas. You can even come across seals sometimes out of the rocks, if you cycle around coastal areas.