Zoning laws in at least some areas in my country mandate that for every floor higher, the surounding open space must enlarge by so much. The result is widely spaced towers.

You are probably looking for a small medieval town. Adding aparment blocks together makes transport cheaper. Hence you can built a walkable neighbourhood with good public transport. You then have green space outside the settlement. However that can be reached quickly in smaller settlements.

Major metros don't have the extra space for hoarding. This is why people suffer the reduced economies of scale and move into rural areas. There's gotta be tradeoffs, and what you pay in occasional power failures or road issues you get back in forests and streams.

Edit: we agree that hoarded greenspace isn't a public park, right? Like, that's almost the opposite thing?

But I mentioned the suburbs because gestures at a forest a bajillion times the scale of Central Park, a contiguous forest area the size of the Amazon

Central Park is awesome - I loved watching the falcons at Mr Allen's place back then, and I had a lion lunge at me in the zoo - but I'm sorry I wasn't clear enough to point out that consolidated park space is the opposite mindset from the hoarded greenspace attached to each individual unit of sprawl of the sort we need to bulldoze for proper space.

But yeah, downvote away.