In fact it does have exactly the same reason for being. Stop arguing non-facts, and microscopic context. There is no walled garden, or gated community of come imagined tycoons here (I'm sure there are elsewhere, but not where I'm talking about).
The town I'm talking about is well outside the city, but also one of the closer ones that actually has habitat, and in particular habitat for endangered species. It is EXACTLY this kind of preservation (and in fact, much larger zoning) that is needed to serve as a counterweight for high-density development.
I'm all for wherever it is already dense enough to basically exclude natural habitats, increase the density. But wherever it is sparse enough to have maintained natural habitat, decrease the density, not increase it.
You evidently have not noticed we are in the midst of the sixth mass extinction event, the previous one being the Cretaceous (~65 million years ago) asteroid impact catastrophe, and this one being entirely human-caused.
Simply encouraging blanket urban/suburban sprawl will only exacerbate that catastrophe. Which would be particularly tragic, since the need is entirely temporary, as birthrates are declining and the problem will be the opposite in a few decades as population declines (and already is in many countries), but the endangered species will already have been killed off never to return.
Personally, I paid substantially higher cost, of hard-earned money, and continue to pay taxes on a lot where 75% of it is absolutely unbuildable - I can't even cut a tree in that zone without permission. If I were greedy, the best move would be to advocate for ending zoning and environmental regs, and let me fill in the wetlands and build multiple units and subdivide. Doing that would easily yield enough money to retire wealthy in less than two years. But fortunately, there is a town where most people value the environment. It was actually hard to find, since there are many, actually MOST towns around prioritized development, because, money.
So, yes, just like Central Park, on a larger scale, this is one of the counterweights, and we pay more and incur large opportunity costs to maintain that counterweight.