Completely agree with your mixed feelings.
On the one hand, I can see a positive side in the fact that it contributes to animal welfare and awareness, as well as overall education. My interest in nature was certainly triggered by weekly zoo visits with my dad.
On the other hand, of course, many zoos still have a long way to go when it comes to the right way of taking care of wild animals. There are many that may just not fit into a cage, no matter how big it is. Lions or tigers, for example, just pacing up and down (this being a clear signal of stress).. Hurts to watch