Noone is going to ride two disconnected bus services that run four times a day and require walking 30 minutes in between.
Add a connection and make them all run every 30 minutes and suddenly it's viable.
Add a metro with right of way that runs every 5 minutes and has 5 minute walk or 2 minute walk + bus coverage to the entire city and why would you spend money on a car?
So you can leave the city. Even people I know who live in cities with decent transit systems that they use mostly still own cars to get away on weekends, do larger shopping trips, etc.
Yeah it's annoying, but it's private transportation! A massive luxury if you think about it long enough. And it means that most houses don't need parking lots.
And make living in cities sufficiently unpleasant or incinvenientand people who can will just leave as they did in the 70s and 80s.
But only the latter group is having that choice made for them and then having their tax money spent on infrastructure designed to burden them with car ownership.
also, like highways it's probably on some level subject to induced demand