All vehicles have things that they are better or worse at, but you overstate the case against bicycles. For example, with passengers, you can add a child seat or trailer to an ordinary bike, or you can use a longer bike designed for bringing others.

Cars also have situations they're a poor fit for: places without good parking, if you have to take part of your journey by another mode (bus, train, etc...) and need your vehicle on the other end, if you can't afford them (including fuel, insurance, etc), if there aren't good roads, if you're too young, etc.