Personally owned folding shopping carts exist.
For those to be effective, you do need good walking infrastructure.
I'd grab one of those except for the fact that I don't have a sidewalk connecting me to the grocery store. Totes end up working better for me as a result.
Used to do this in Belgium. Still less convenient than driving, and kinda annoying to use during a Canadian winter.
And again, more limited space.
I commute by walking (1h per day) and typically avoid the car when possible, but for groceries there’s just no way I’d go back to walking to and fro.