There are all of these layers of users to be considered: there are citizens who want to get places, and the city who has to build and manage street infrastructure and public transportation, and the commercial developers who are building the properties and their parking, and the business operators in those commercial developments who want those citizens to visit their business for commerce.
It is that last step that I wonder about: sure, some businesses have the luxury of building their own facilities and having some understanding of the parking they think is appropriate; but it could also be that the developer building the property doesn't have a deep understanding at the start because they don't know what the tenant mix will be like, or that might change over time.
I don't know how a city could know any better than a developer, but perhaps a city could represent citizens in ways that are not purely financially motivated as a developer might be inclined with their responsibilities.
Everything about getting someone from one place to another has a cost, and of course that includes making a place for empty vehicles to sit idle while their drivers are doing something else (that includes the cost of the garage or carport or driveway at home). I don't know how to share those costs in the most fair way.
It doesn't seem right that someone can put in a very popular business and not contribute to the capital cost of parking facilities and either crowd a residential neighborhood or choke out a publicly accessible parking lot. Even if we try to say the parking fee should cover it, or the bus fare should cover it; the reality is that parking garages and public transportation are both capital-intensive things to build and take a long time to pay off; if ever. It happens that you see such things built just on their own, but that is more rare -- parking is normally built, even for-pay parking, in support of some other endeavor that is generating more revenue; whether that is an office building or a shopping center. Same with public transportation -- it is not particularly built to turn a profit, or even pay for itself, but rather to support the other aspects of the city. Of course, I know there are exceptions.
I'd like to see a way to distribute the costs of bringing people to businesses in a fair way. Requiring parking was one way to make businesses pay for one part of the expense of getting them from where they were to the place to do business. Only paying for the cost of hosting the empty idle cars is not much, but it's more than nothing. It is probably also antiquated, and so we probably need to figure out better ways for businesses to pay their fair share of the costs.