But on the other hand, the coalition of rich neighbors could organize a counter-offer to buy out neighbors who want to leave. A bit like lands are bought up by conservation groups to prevent development. Put a price on how much you want to preserve your neighborhood.
They could even buy out the developer who purchased a spite sale, unless there are deed restrictions in that sale. Most developers are also doing it as a business, not for idealism, so it there ought to be a price point where they see it is more lucrative to fold than to go forward with the building project.
I'm not sure I understand the economic effect of something like this. At first blush it almost seems like the same feedback loop as land value taxes. But, it also creates a game-theoretic scenario where the coalition is pumping up the price of their own neighborhood and increasing the potential gains for the next defector, at which point the values could rapidly unwind if the coalition loses its way.
Free money for defection and could easily exhaust the resources of this coalition.
You really do not realize how big (or small, rather) apartment complexes are. 100-unit building is the size of 6-7 single family homes (or maybe 3 McMansions), and maybe twice as high. It would barely be noticeable in such neighborhood.
See this for example: https://ctexaminer.com/2021/10/23/100-unit-apartment-complex...
With parking minimums of 2 spots per unit, your standard 800 sq ft apartment requires another 600 sq ft of parking. And units can be stacked relatively cheaply, parking can't.