Indeed. Our elevated trains are excellent (even though everyone complains) but even with recent expansions they don't serve huge swaths of the city.

https://www.transitchicago.com/assets/1/6/ctamap_Lsystem.png

If you're on the NW or SW sides in particular, you're going to need a car.

We're getting more and more bike lanes but they're also very unequally distributed and biking is...not great for winter.