I don't think we need to give up cars entirely, but I also don't think we'll be able to address the negative aspects without some amount of change.

An example: I live roughly 200m from the Costco in the center of town, but there's a major 4 lane road between us. Walking would be so convenient, but it's so much safer to drive. A footbridge would address this without impacting drivers. I have no intentions of giving up my car, but this particular activity would be so much nicer without it!