Ten minutes of small talk with the old man on the bench might be the only conversation he gets today.

Loneliness in old age is mostly made of days with nobody in them. Not tragedy, just a long stretch of hours where nothing requires you to speak, and the effect of that accumulates quietly. Ten minutes of ordinary conversation is not charity in that situation. It is the difference between a day that had a person in it and one that did not.

If you pass somebody who clearly has time, stop for a bit. Talk about the weather or the dog or whatever is in front of you. It does not have to be meaningful, only to be a conversation.