It is very much important to the developer - whoever buys the land wants to know that their employees and customers can get there. That means there needs to be enough parking, transit, or pedestrians. If it is in a car centrist area that won't buy if there isn't enough parking. Downtowns can get by with less parking only if there is great transit to bring people in. Developers are not stupid, they know that if there isn't enough parking property values go down.
This is the root of the issue, which people often want to ignore - it's a class chicken'd egg problem.
The "there is no parking at all" wonderlands can exist (even NOT counting artificial ones like Disneyland) - and the "everything is acres of parking and there's no street parking at all" also.
The question is how you get from one extreme to another - in a way that does NOT require you to redevelop the entire city Simcity style, nor puts onerous costs such that all development is stifled.
Part of it might be that if the parking lots/garages are not heavily used, or not used much, they'll "redevelop themselves" - but that likely requires making transit and other options better which is difficult, expensive, and often politically unsound.