Are you really curious?
It's the same reason that if Oprah took her billions to try and solve some global problem with her husband Stedman, many mentions of the work they were doing would not mention Stedman.
One is a famous individual who built up an obscene fortune, and the other person is married to them. And despite how involved their partner is deploying that wealth for the good of the world, people are just not going to mention the less famous one who didn't build up the fortune as often.