It gives a sense of self sufficiency. How to explain?... maybe you dont think the way I do.
I think it's an illusion of self sufficiency (cars are useless without a whole lot of infrastructure that no individual con provide for themselves) so I guess I don't think the way you do.
Anyway, I think for at least 80% of the people that use them in Poland, a car is more a luxury than a necessity. They're a powerful status symbol for many Polish people (much more than in the US) but they're a lot more trouble keeping than in the US too. Gas is more expensive, roads are usually in poor shape, Polish people are mostly awful, reckless drivers with no basic understanding of basic road courtesy, car theft is a real fact of life (not as much as it used to be, but it's still something you have to think about) and trying to park in cities is an exercise in frustration/rage management.
On the other hand, public transport in cities in Poland is better than anywhere in the US and taxis are pretty cheap.
You might decide you want a car to travel around the countryside but basic public transport supplemented by the occasional taxi will probably allow you to enjoy your stay more. I reccomend buying monthly (or 3 or 6 month) passes. It's cheap and you don't have to think about fares, you just jump on whatever bus or streetcar is convenient.
Oh, also. Suburbs (in the US meaning) don't really exist in Poland. It's hard not to be in easy walking distance of stores unless you're way out in the countryside.