Cursor made Grok Bot and is working on the Grok models.
I wouldn't say it's obviously unsuccessful.
Considering that the biggest and most successful play for SpaceXAI in the AI space has been "Sell compute to Anthropic" I also wouldn't say that all of the grok junk has been obviously successful, either.
The team behind Cursor and their data were worth $60 billion to Musk, not the app itself.