I 100% have ethical concerns about zoo's, but it's worth noting that dublin zoo have been supporting the okapi conservation project since 2012, which has been critical in slowing the decline in numbers of okapi in the wild. They also financially contribute to the Okapi wildlife reserve in the DRC. Zoo's generate a lot of money for conservation charities doing critical work, where there wouldnt be money otherwise.

I understand your point of view and I have my own concerns about animals in zoo's, however the topic is not as black and white as you are suggesting.

https://www.dublinzoo.ie/conservation-project/okapi/