The availability of buses in your area is, of course, a factor which needs to be considered.
When I lived in Sheffield I never bothered learning to drive because there were 13 buses an hour from stops near to my home into the city centre. There was also a good evening and Sunday service, together with a skeleton service running throughout the night. (There were even buses on Christmas Day). It was also possible to get a taxi quickly at any time of day or night, without pre-booking.
One of the first things I did when I moved to Suffolk was to take driving lessons, pass my test and buy a car. In some parts of coastal Suffolk there's only one bus (to and from the nearest town with shops) per month. In those same areas you can have a taxi at any time you want it but only if you book before 6pm (because that's when the taxi offices shut). So if a friend, who lives a few miles away, phones you at just after 6 to invite you round for a drink and some supper, there's no way of getting there unless one of you drives.
The part of Suffolk where I live actually has a good daytime service (every half hour) but there are no evening buses to get me to pubs, cinemas and theatres. (Fortunately there's a train service but that doesn't help people along the bus route who don't live near to a rail station). Having a free bus pass isn't much use if there aren't any buses!