What is cursor still raising money? There's probably some VC understanding I don't get yet. 

They raised 900M, they're on track to earn 300M per year. 
I'm not sure the margins but there's no way they spend 1/3 of that. Say without any growth, they earn 200M per year. 
In five years, they would have at least the investor funds. If their ideas are indeed wrong, they it would churn by then. But if they're right and the current pitch they use to raise is true, they it means they could just implement it without needing more VC funds.

They're not training models, they loading the model cost on the users almost directly (either via subscription or api key)
So again why do they need to raise billions?