I think you are right, it belongs to players from other times to know various modalities, today only or almost everything is carried by holdem, I think it is due to the televised and great diffusion that it has had years ago.Players who have good experience in all kind of poker games are usually from the older generation. Newer generation players are mostly focused on No Limit Holdem or Port Limit Omaha usually. If i need to select one of the players who are currently at their top shape for mixed games it would be Phil Ivey.