> I've always wondered why there couldn't be standard containers for products like jam, wine, butter etc. where the containers are designed to be easily washed and reused.

This used to be the case in my country back when I was a kid and when we were still under (nominal) communist rule. Almost no jars or bottles were thrown out after use because that would have been similar to literally throwing money away, what was usually happening was that our parents would send us, kids, with a bag of empty milk bottles and jam jars to the closest general store and we would receive some money in return for said bottles and jars (not much of a sum, I agree, but it was better than nothing).