hmm.. a theme seems to be dveloping here.
someone says - i have ordered my life in ways X, Y and Z so i don't need a car...which to my mind means there were also choices A B and C they could have gone for if they drove - the job only (seriously) open to drivers, the house in an out of the way spot - the leisure trip easy with a car but a bloody nightmare without ....
people believe non-drivers get others to ferry about, because they know non drivers who get others to ferry them around...my uncle and aunt were ferried around by their daughter after she passed her test....my BIL got my sister to drive evey time they needed to move house...perhaps not true of you - but true of every non-driver i know IRL!
and there was never anything more anoying than being told i didn't need my car by eco-entalist ex-students resident 20 minutes walk from their place of work who claimed they didn't have cars on principle (evidently, they just didn't need them) - no doubt most of them now own cars unless they still live in town. particularly annoying when they took the bus to work to avoid said 20 minute walk.
Incidentally, car drivers are, on average thinner than non-drivers, though that is most probably due to linked socio-economic factors.
although you say taking a bus with small kids is not impossible, it is far from fun...taking two kids in enormous pushchair...load kids - walk to bus stop, unload them (small into sling, large on pavement) fold enormous pushchair (actually impossible with 2nd seat attached) with larger child milling listlessly at the roadside. get pushchair and child onto bus - pay driver (with third hand!) ....find place to put child & pushchair (with 2nd seat attachment in hand as well) -repeat procedure at other end. Return journey bearing shopping even more difficult....
This is why i prefer to walk into town, or if it is not walkable, car then walk.
Once you have bought the car, the cost of using it is generally comparable to public transport.
And it is all very well to go on about publictransport, but the problem is it never goes where you want to go - there is no bus from my house to my mums, or from my house to my work via my mums (which would be ideal, but would actually loop back on itself) - had here been a bus provided from home to the work place i first bought a car for, I'd have been the only person on it!
And don't get me started on how you used to be able to use small local shops - because no-one loves Supermarkets more than my Mum, who looks back on the days of lumping 4 kids round small, expensive shops with a rubbish range of products (no curry paste!) and getting gossiped about by the biddies on the till before she was even out of the shop with abject horror.