There are plenty of local places with a ton of domestics and a few wild animals - which started out as a visitable local "farm" with local domestics, then started getting foreign domestic races (e.g. Llama, Yak) to attract more people then ended up with a few common wild species (often parrots, wallabies, maras, etc). The Ferme Exotique near Bordeaux developed in this kind of pattern, for instance.
Another common thing is zoos focusing to some extent on saving rare, endangered local domestic breeds - Nordhorn in Germany is such an example. Nordhorn is roughly half domestics half wild animals, and it is very popular - moreso than neighbouring Rheine, same size but with no domestics. It's not always true than zoo focusing on domestics are less popular.
Here are a few examples of other noteworthy things which have to do with domestics : the architecture of domestic zones in many zoos are quite unique, since those places often try to recreate farms - in fact, in a place like Vienna, the zoo's domestic barn is actually a very old barn moved to the zoo for this purpose ; and there are a few places, like Zoodyssée in France, mixing domestics with local wild animals to talk about the biodiversity of old, pre-industrial farms which allowed many bird species, rodents, and small predators to live in the ecosystem created by farmlands ; and which are today locally endangered because of industrial farming.
And, on top of the classical domestic, there are exotic domestics which are often exhibited alongside wild animals in zoos - of which we already have a few like the llama, but we could use many more : the watussi breed, the heck's auroch, the domestic yak, etc.
So, yeah, there's a bunch of interesting ways to exhibit domestic breeds on top of the classical "mini-farm", all of which would be interesting in a game like Planet Zoo - for all those reasons, I'd buy a decent domestics pack in the heartbeat.