I think if we're not providing explicit space for these fairly large design spaces, there's not a lot of incentive for people working in those spaces to transition to the Itch community. If the goal is to expand the TTRPG community on itch, it seems strange to me to stick only with what's already popular on here. But this is ya'lls show, just felt like it was something to discuss.
Edit: just as an aside, D&D and 5th Edition tags have about 8 or so games on Itch while Belonging Outside Belonging has 4. I'd say the community is def. there if its a numbers thing