I have not seen a rich man coming to the public to preach or teach people how to become rich. But those who are poor or middle class or the educated elites would interview the rich and the wealthy people then write motivational books for the research they have carried out.
you won’t find a lot of the rich people writing these motivational books or giving out a lot of speeches because why would they want to share whatever they did in order to get to where they are? that would be very kindhearted but in reality kindness isn’t what helped them bring success to themselves