What are the most likely reasons or attractions in European zoos that would make Australians and New Zealanders willing to go to Europe to visit European zoo(s).

Inspired by a journey of an Aussie
Not sure who that could be?
My answer is 'all of the above', other than that I don't care about different giraffes (indeed, I lean towards arguing that all the species should be maintained as a single population of 'zoo giraffes'), and koalas are hardier than people seem to think.
I like seeing new species, but I'm not super-specific about what they are. When I first started my recent burst of travels I had giant anteater, giant otter, Siberian tiger, okapi, bonobo, proboscis monkey, slow loris, aye-aye, river dolphin, pangolin, naked mole-rat, kea, kiwi, emperor penguin, whale shark and manta ray on my list, though it was always an informal list that didn't govern which zoos I visited (other than going to Atlanta specifically for the whale sharks). I'd already seen my beloved hornbills for the first time in my only previous overseas trip to Bali in 2012.
I've ticked off all of those species except the river dolphin now, so it really is about visiting the zoos themselves, as opposed to hunting life ticks. I also don't keep track, as some people do, of what animals I've seen and not seen, other than particularly notable species like those above.
Why on earth would we travel across the planet to see something we can see in our own backyards? And in larger numbers. Sometimes I really don't understand how some of you people think.
Hix
Tell me about it. During the mating season I have to wear armour to go to my mail box.