Ha, within a 15 minute walk? I’m going to guess you don’t have kids.
So parents need to pack everything up daily for their kids to go play (at least for the first N years of life until they’re independent enough to go do a 15min walk on their own) or be taxed for it?
I have a public park across the street from me.
I spent $20k converting the side of my house into a playground for my kids.
The QoL impact has been massive.
It’s gated in by a 6ft perimeter brick wall with a door that we put in that opens from the kitchen.
In the morning, my 2 year old can unlock the door to the side yard and go play before we even wake up.
The side yard lets our kids play without us needing to supervise. It gives them strong early independent play and gives us space to get life sorted out while they are entertaining themselves (chores, bills, etc.).
The park across the street does none of that, it is not interchangeable in any meaningful way.