Since I can walk there a few times a week, I tend to buy less grocceries at a time. The weight limit helps me budget for the week by preventing me from buying more than I need.

You need to rethink how cities are designed for walking to grocery stores to work. It won't in the US, because everything is designed for cars. But if a city is designed right, you won't need to go miles before finding a grocery store. You can take a cargo bike to haul more things at a time. You can stop by shops on your way home from work to pick up a couple things and stick them in a backpack.

Cities designed correctly reduce the burden on those walking or biking between points of interest that are no more than 1 or 2 miles away.

Why do you think everybody lives so far away from their nearest grocery store (in the USA)? Well, people did live close to their nearest store until the car happened, which enabled suburban development, and then enabled big box supermarkets which killed the little shops on the corner.

No one is expecting you to walk to the shops given how fucked your country is. Either the country repairs itself or the rest of us just forget about it, because the USA does look like a lost cause