I’d posit that more people are playing more and learning chess than ever before, thanks to networking and AI assistance. And computers have only beaten us at computer chess. Human chess is always an experience for learning about the other person, or flipping the board and walking off in a huff.
I don’t know so much about Go and it’s not surprising that Lee Sedol became pretty demoralised, but the generation coming after him alongside computers are going to see new possibilities that had gone unnoticed in purely-human Go, extending the game for everyone.
Of course Magnus would crush be, but the existence of the best player in the world doesn't have any impact on the health of the game community as a whole. Magnus would crush me even if he had never used a computer, but in the latter case I think his games against other players would be more interesting as well.