It's debatable whether I am in a suburb or not at the moment - I am barely technically within the city limits, about 3.5 miles from the middle. But anyway, per Google Maps, I'm about 8 minutes drive from work, 54 minutes bus ride, and 62 minutes walk! Bicycling is estimated at barely over 20 minutes.
When I lived 10 minutes walk from work, the bus took about the same time, but waiting for its schedule meant practically speaking it was more like 30 minutes. It felt a little safer than scrambling across three highways, but after a bit, I couldn't stand the wait, so I went back to walking, and then to driving.
If I lived in a popular suburb further to the north, then I wouldn't be able to ride the bus at all (although that's too far of a commute for me by car)
So, across the whole range of commute distances, I can't see any situation where riding the bus makes sense. It either takes essentially as long as walking, or isn't available at all.