Everything has it's place, in an ideal area if I was wanting to go a short-medium distance I'd go on a bike, if I wanted a drink or to carry more than practical on my bike or to go a medium length I'd take public transport, and if I wanted to take a lot of stuff, or go in a time sensitive manner, or not want to worry about the last bus, or go somewhere rural I'd take the car.

I don't think good public transport can replace cars in all situations, but it is an extremely good option to have for situations that suit it (which for most people is likely most, but probably not all, of the time).