That only applies if you’re transfering the soup out of the container to eat. If you plan on eating straight from the tupperware, round is better for soup

It’s very hard to get all of the soup out of a square container, because a spoon won’t reach into the edges properly

If you don’t own a car, or can’t drive (at the moment) for some other reason, in a lot of suburbs in the US you literally don’t have a choice.

Where I live in Germany there’s also a lot of supermarket delivery, but they’re generally picked and delivered by people working directly for the supermarket, not random gig economy dudes of the street, so since they have access to the stores inventory system they will automatically know what is available (and since the order app also has that access, you can’t even order anything the supermarket already doesn’t have in inventory at the time of ordering), and either automatically cancel, automatically substitute or send you a notification to pick an option if something is out.