What would you think about a city comprised of only 30 floor mixed use buildings each one separated by enough parks and forests that the parks and forests were around 75% of the city area (excluding simple roads between buildings)?

A radical take on a 15 minute city, but the point being everything from schools to jobs to groceries is extremely close, and there's a large fixed cost to going elsewhere.

If one building has a footprint of 2 acres (generous) then we're actually only talking 350m 90m (assuming a 2D grid and not a line) between the centres of each building. 300 people per building would give a density about 9000 people per square km, well above most North American cities.

Could foster community because people will more likely live, work, eat, and learn locally.

Would help the environment through less cars, more forests, and less impact on wildlife.