Hello @wiseagent
This is an interesting question. In a way I think we have all come to this platform with the intention of having an additional economic income, for many it has even become the only way, however. Getting here and staying here are different things. Because the learning path to a good income can be slow. Much more than money must be found. Because even from well paid jobs people get tired and leave.
The points you mention are important.
It is a sharing of knowledge, you learn a lot by reading other publications.
And you enjoy sharing what you have to say. And of course, money is important, because spending hours on something just for pleasure would be difficult to sustain.