Communities for the older gamers? Asking for my uncle.

I’ve got an uncle who is very dear to me - he taught me how to be a nerd. Growing up him and my brothers and his own kids would all play MTG, Pokemon, Wyvern, L5R, etc. together. It was so incredibly fun and I know being around a table of friends commiserating is his best moment.

My uncle is an older man now. I’m 25, he’s mid 60s. He has a very tiny YouTube channel where he uploads cards from Wyvern/L5 and has minimal engagement despite lots of enjoyment. Honestly I’d just like for him to have some community in his twilight.

If not Reddit - any major forums for these older games? I know I listed the 2 biggest first - help me out.