On the other hand, I don't think I know any millenials that don't have an extremely overbearing HoA that forbids anything other than a grass lawn.

I looked it up and a couple of states have laws against HOAs from forcing your to have a grass lawn. Alternatives can include native plants, drought tolerant plants, xeriscaping, vegetable gardens depending on state. The states I've found are California, Colorado, Florida, Texas and Maryland, Nevada.