You can't have something be a necessity and a luxury. An iPhone is one or the other, but not both.
I think you're generally OK if most of your activities work via transit and Uber. As you suggest, as well, kids and pets probably make things more difficult.
I do own a car but that is only ever used for traveling to another State or to get into more remote parts of the mountains. For anything else, using a car would be inconvenient.