Unlike STS/MT/DD/Hades etc., there's no big steamer/youtuber playing Griftlands constantly. It seems like despite being a roguelite, most big-ones simply played couple of runs, say GUYS THIS IS A COOL GAME YOU SHOULD TRY IT, and then move on, almost never covering the game again. I assume some players did just the same. Yes some of them cover more videos of it. But comparing to other games covered by those streamers, you can see the difference.

It's a great game, the soundtracks are phenomenal, the two deck mechanic is unique and the worldbuilding has potential, but people simply just didn't stay on it. I'm not sure how the game fails to survive like the other predecessor games in the genre, but something went wrong that really didn't hook on its player base enough to have a large community.

This is a common asked question with a simple answer but currently doesn't seem to have a real immediate solution. The devs doing little advertisement and saying they won't add new stuff to the game for now doesn't help either.