He didn’t give “back”. He gave. You can give any thing you want to anyone you want, but only give back something that was given to you in the first place, and I’m fairly sure those “essential workers” were doing their jobs ie being paid as teachers.
He did all that on his lunch hour? That took some effort, I’d say just for the time it must have took, but it was very generous of him. He must have a very good job..the last job I had sure didn’t allow anywhere near that kind of generosity; it was a meager living for just 2 people.