All the people who post here do so with no payment.
Personally I do it because I have a love of mathematics and also a love of teaching.
I can do both here. I don't get renumeration, but very occasionally I get greatly rewarded by the people I have helped.
The best rewards, the ones that mean the most emotionally, are the positive impacts that we have on another's life, and it is shown to us physically or verbally, not financially.
Of course most people need to be paid for what they do and I am not criticizing that. But it is not the paycheck that determines the degree of job satisfaction that a person gets.
I will add that I get to interact with other like minded people.
There is a great community of very generous people here.
It is an great honour that I can be here with them.
Thanks for recognising the dedicated people who are here :)