I've spent wayyy too much time thinking about what I'd do if I won the lottery and the thing I always come back to is building a neighborhood for my friends and family. One thing I'm pretty settled on is having an HOA but with very different rules mainly surrounding land use.
Everyone gets a plot of land but only X% of it can be structure. That's a normal rule to have. But also only Y% can be lawn grass and Z% must be native plants.
(Additionally: no gas lawnmowers/leaf blowers/etc, power must be 80%+ renewable, and no Ring/similar cameras)