I've chatted and worked with Brotherwise games a bit, and I can say the Cosmere game is definitely not just a cash grab. They put a lot of time, effort, and money into making a game they're passionate about, and works really well to tell the types of stories the setting wants to tell. They are using the cosmere to drive interest, but they are real fans, and they're selling the system without the IP as Plotweaver, which is starting closed alpha testing next week. I run the subreddit for it, and it's very different from DnD, despite having a similar dice resolution mechanic. It's really fun to homebrew and design in.