If I take a bus, it would take me ~20-25 minutes from where I live to my work. On Sundays when the traffic is very reduced, I need around 10 minutes for the same route. In working days it is 15 minutes.That makes a guestimate that the bus is 50% slower. Taking length of ~4 cars that would make the impact of 1 bus = 8 cars. Now what's with the other 30 cars?
I prefer the bus as both stops (home/work) are damn close to where I live, so I don't waste time in parking, nor do I care about the other drivers. I prefer the car if I have some other things to finish before or after working hours.
As for not subsided public transport we have private operators who drive for a cheaper price then subsided city owned company.
If I'd have to go anywhere outside of the city, I'd prefer my car for various reasons, but mainly flexibility.