Due to the recent boom in Dungeons and Dragons, and open markets such as Drive Thru RPG and the Dungeon Masters Guild, it’s easy for anyone to create a product and put it online for sale. So there are a lot of them on the market right now!
If you want to stand out from the crowd, you’re going to need a team. You’ll need great writers, people with ideas beyond what is typically seen, and ideas that can span well beyond even your first initial drafts.
Start with a world, a setting in time and place to anchor your ideas. You need artists to help bring this world to life, people who can translate those writers’ ideas into something tangible and marketable for people to get interested in.