I think what helped Roll Player Adventures was tapping into that older style of TTRPG, the kind you used to remember playing with your friends at the table, but packaged in a new and interesting way.
Don’t be afraid to find new and different ways to experiment with the TTRPG setting and what it can mean. It doesn’t just have to be a manual or book; it can be a board game, a product, a setting. Anything that involves rolling dice, laying out player stats, and exploring a world can be a TTRPG. Open your mind to the possibilities, and give people something that they’ve never seen before!