> Public transit is rarely a time saver for people who give up their cars in favor of public transit.

It saves time when you don't put 10-lane motorways and in your cities nor turn them into parking lot wasteland.

> In what way? Car break-ins presumably go down when there when fewer cars, but does overall crime drop?

Public transport reduces inequality, which is the main cause of crime. If you have whole groups in society that cannot get what they need working within the system - some of them will work outside the system. Public transport makes working within the system easier (barrier to entry to work/study in the good places gets lower). It also smooths around the strict urban class divisions (it makes sense for rich people to live in the city, which makes the elites more likely to invest in the city, which makes it more likely for non-elites to be able to work with the system).

The opposite is car-dependand suburbs + crime-ridden inner cities with no way out other than crime.