Earlier quoted context omitted.
The space a vehicle takes up is also essentially a public good. Your argument can probably be fairly recast as "everyone should have to pay equal costs in time if they want to use the road". And then never mind that a congestion charge is more predictable than sitting in congestion.
When I was down in Dallas, they have two parallel roadways - one which is the paid-for express version and one which is free. You can pay to get on the less-congested highway or choose to take the more congested, but free, highway. Maybe something like that for NYC would work? But with NYC's layout, I have no idea how that would work. Dallas has plenty of space to make that possible.
You can even take a helicopter some places.