they are using their assets to make money, period, they use their assets in the game therefore people are influenced atleast a little bit TO purchase other assets. They could be sued, and it would be worth it depending how much they’ve made. If they’ve made a few hundred thousand over the lifetime (not unlikely) they would likely make money off of it, especially if they sue for legal fees as well.
But at any time they can DMCA and roblox will take it down and keep it down because if they dont ROBLOX will be sued. Valve hasnt really been interested in doing so, but if they are aware of how much they make they will.