A few years back, my son got cut from the high school basketball teams. He did not make the first team (that was expected), but he also failed for the second team--despite a lot of work to enhance his basketball skills. He was very disappointed.
I went to the school to ask some questions. The co-ordinator said that they would put a third team together if there was someone to coach them. And that is how I became a high school basketball coach. My son and about 10 other boys made the 6:30 a.m. practices and got about 10 games in before COVID shut the league down.
I really didn't need the hassle of being a basketball coach. My point is that many of us volunteer for things that really don't have direct benefit to us. Yes, there may be some self-interest involved, but there is still a lot of altruism.
There might be reduction in volunteerism than there was a generation ago, but there still is enough altruism out there to make this work.