The “Linux demographics” were a bunch of 20-30 year olds who are now 40-50.

Same with the “Free Software” crowd - those 20-30 year olds are now 50-60.

Aging demographics that broadly failed to attract any interest from the next generation. Honestly though, why join? There’s nothing inherently attractive about either community. Hang out with toxic gamers on Discord and join a team, or hang out with toxic old nerds still on IRC for ideological purity. I know which one wins. Even professionally, I’d rather join a model train community.