Last time I was in Germany I saw elderly people going through garbage bins in the park I sat at. I think you overestimate the safety net in Germany. In my European country the elderly sit at cafes drinking coffee, not going through bins.

Update:

Every street corner has a yellow garbage bin for recycling. That is where your plastic bottles go. Seems like a better system than having elderly going through bins.

Maybe in your country they also don't have a deposit on bottles/cans, making it pointless to go through trash cans?

Not OP but many people eligible for social benefits don't seek it, for all kinds of reasons (not knowing about it, pride, ideology, peer pressure, ...)

Keep in mind that not every old person who searches garbage bins is actually poor. Some of them just have dementia. I personally know such people in my home town.

That's why I said "mostly"