I'd say many pre Fischer world champions did a lot. Other than Vishy and Kaspa I actually find that most recent world champions haven't contributed quite as much to the wider chess situation as their predecessors. Most of them had a short tenure and are widely unknown, whereas that one most well known one just gets into all kinds of scandals and plays amazing chess (a joke before someone comes after me). Other than that he doesn't really affect chess. And I mean "affect" in the way Vishy is a chess hero of India (the country that's currently dominating the chess scene), Kaspa contributed to the world's chess education with the "my great predecessors" series, Bobby did that whole cold war thing, and created chess960. He also said some pot stirring things about stuff (chess included).
A lot of the champions before him wrote great books, and came up with revolutionary theory. These things to this day are recommended to anyone who's become semi serious in chess. They are true icons in a way that modern chess players can't really achieve yet (there are exceptions of course, but I'm trying to make a point so I won't get into that).
Of course I acknowledge that where these so called "icons" contributed to the educational side, modern chess "stars" have done a lot for the publicity of chess
Magnus Carlsen duhhhhh, I mean ok I dont know the guy so much but like come on, obviously its him: )
Uhhh, I'm sorry but I think that you have misunderstood the topic of discussion.