For the majority of (urban) people it’s definitely manageable. More than 50% of all households in central Berlin own no car, numbers rising.
I used to own a car, and the tipping point from “I can’t do that” to “no problem to do that” was selling the car. It’s an acquired habit for most of us. I now own an umbrella and a good waterproof jacket instead.
You don't just go to buy STRICTLY what you need today. You buy something like 10% over each time. Within several weeks of shopping you'll have a full fridge, heck, even a full pantry.
Then you only need to top up when you go each day. And I'm being generous, you can go every 2-3 days, even.
There are comfortable solution, you need two things:
1. An environment that helps (most European cities).
2. A bit of planning/flexibility/smarts.
If you don't have 1. you're dead in the water, from the start. If you don't have 2., well... get them :-)
There's so much of a bubble here sometimes. Narrow minded...dude, not everyone is a single, childless, wealthy knowledge worker that can waste their time to do this.