I mean, we have pretty overwhelming evidence that people will alter their travel behavior based on incentives and available capacity.
We add more lanes to a highway, and get induced demand with people choosing to drive more. Road diets restricting road capacity lead to reduced demand, with people driving less. There's a ton of research on both phenomena. When the 405 was closed for a weekend due to construction, Los Angeles was told to expect carmageddon. Public transit saw record-breaking ridership levels that weekend, and traffic across LA actually decreased as a result.
Drivers routinely change their driving route based on traffic congestion, and it's not uncommon to choose a slightly longer route to avoid being stuck in a traffic jam. Sitting in traffic feels more stressful, particularly on a highway where everything about the road design is telling your brain that you're supposed to be moving fast but aren't.
If we wanted to, we could build robust public transit systems that are more than capable of moving most people to where they need to go with minimal delay, convenience, and comfort and that a large percentage of the population would want to use.
Instead, most of North America has anemic bus systems that couldn't be more antagonistic towards their riders if they actively tried. A bus stop sign on the side of a four lane stroad that lacks sidewalks--the very thing that would enable people to safely access said bus stop--sends a pretty clear message to riders "we don't care about you, and if you die trying to board your bus, well, that's just how it is."
In any case, you're conflating the desire to move around with the desire to move around by car. They're not the same thing, even if seventy years of urban planning have assumed otherwise. Beyond that, we travel between places because we want to do something when we get to our destination. That's the goal, and the mode by which we travel there is simply a means to an end.