My group that plays off and on are me, at 49 (the youngest ), up to 54. In all, about 7 of us. I didn't start playing until 1993. Before that, I only played DandD from about 1982. When we've gone through patches were everyone wants to play my old Waterdeep DandD campaign, they make me use all my RoleMaster stuff to make it better (the campaign is 2nd edition DandD to this day -- with HEAVY mods from role master). btw, as soon as I played RM and used 'Perception' for the first time, I was like "DandD needs this bad!".. and now, of course, they have it in 5e..(though they may have had it back in 4 -- IDK)
Oh, and might I add, I think that RM has a very heady approach to its rules and always seemed to require a lot more mental investment in order to learn how to run. As for players, however, if you could just get them going and know the rules for them, they could enjoy the game quickly. So, maybe the veterans among us really need to reach out to younger crowds, get them playing, and train up the best ones for GM'ing.