[graeme]

True.

This seems related to the general decline in fitness of the American population, assuming OP is American. Grip strength has declined massively since the 1980s.

A short walk with bags shouldn't be hard or even unpleasant for the typical adult.

[cortesoft]

I am shopping for a family of four, and often have two small children with me.

It was a lot easier when it was just for me. I now get enough groceries per trip that there is no way I could carry them all home by myself.

[graeme]

Fair point, I think most families of four might have moved out of my neighbourhood. There are a lot of families of three, but I think they move elsewhere once there is a fourth.