Ah, HOAs, the importing of fascist neighborhood Gestapos into American life,
so great.
As always, an HOA should only exist for one single thing alone and do absolutely nothing else: ensure everyone takes care of their yard. That's it. Put whatever trees or rocks in it you like, it just has to look nice so home values are maintained. No weeds. That's it. Nothing more.
But no HOA in the history of mankind has ever been able to limit its own power within those boundaries.