The beginning of a friendship, the fact that two people out of the thousands around them can meet and connect and become friends, seems like a kind of magic to me. But maintaining a friendship requires work. I don't mean that as a bad thing. Good art requires work as well.

The quote is suggesting that forming a friendship requires effort, just as creating good art requires effort. Initially it may appear like magic when two people randomly meet and form a bond, but once the friendship has formed it takes work to keep the friendship strong. This work is seen positively, in the same way effort and skill is needed to produce great art.