In order for a public transit system to be convenient you need a LOT of density. You also need speed. The two goals are fundamentally at odds with each other. That’s why a lot of people prefer cars. No one likes traffic or emissions, and cars are way more likely to kill you, but damn are cars convenient even in urban environments.
Any plan like this can have all these numbers talking about how much space could be freed up but they need to address this fundamental problem, and this article failed to.
Now what interesting is the rise of self driving cars. I’ve often see paid parking lots and think within 20-30 years they will be out of biz. A few large operators will emerge and park their cars overnight at some owned large lot far out of the city to recharge, maintain, etc, and there won’t be much need anymore. So that could be a path to what author is talking about, long term. Of course does nothing for parking lot owners who just hold onto the property speculating...