Well, why don’t you compare? Open up Google Maps. Choose two points in the suburbs, and see how long it takes to travel between them by car versus by public transit.
I did the same, between my apartment complex and a nearby business, and the estimates are 12 minutes by car and 47 minutes by bus. Main problem: there’s a transfer in the middle of this route where I’d have to wait 11 minutes for the next bus to arrive.
I tried again with a different business, and got a direct bus route with no transfers and exactly the same route I’d take in a car. This is the best-case scenario for public transit, but going by car is still significantly faster: 10 minutes by car, or 17 minutes by bus.