This would be controversial, but I don’t understand those who are against all zoos and sanctuaries where humans get to come in contact with animals.
My friend who works at WWF would make a better argument, but I would try. Without doubt, natural habitat preservation is always the best and preferred option, but it is not always possible, especially in poor countries (and incidentally “humans first” folks usually fight efforts to limit human expansion by government and conservation nonprofits claiming social justice grounds).
Also, education is important – our local wolf sanctuary picks a single “wolf ambassador” each year who gets accustomed to humans and attracts the visitors who come and see the wolves (behind fences) – this creates funding for their breeding and release program that saved and repopulated hundreds of wolves in the West – and those other wolves are only heard, but not seen, by the visitors.
Finally, most people don’t have the ability or means to travel, and letting children experience the wonder that the nature is super important for their appreciation for nature as adults.
Now, endangered exotic-pets trade and circus animals – that’s fair game and there is no humane reason they should exist.