IMO if the SDMB community wants to get new/younger members long-term you (we?) are going to have to migrate to one of the major social media platforms. Also probably the most likely one, reddit (while of course a cesspit in many ways and also a major change from a lot how the board works now) can be a good home for effort-posts and in-depth discussions on a lot of subjects if the community/mods of those subreddits are serious about cultivating it.