Not counting nice walks in prospect Park, I can get on the metro north train and go on a variety of hikes. It’s not 20 steps, but I also get all the other benefits of a city.
Also Manhattan isn’t known for smog, and there is a lot more to New York than Manhattan. Go look at like park slope or Astoria
Also switched to Linux (popos) this month. It’s been fine. Games work. Browser works. No complaints, really.