Over 40% of D&D 5e players are under 25. How do we get the OSR to tap into that demographic? 

I was watching Professor Dungeon Master over at https://www.youtube.com/channel/UCD6ERRdXrF2IZ0R888G8PQgand I realized he had it right. A sandbox is about choices, but not limitless ones, at least not if the DM wishes to retain his sanity ;)