How hard would it actually be to debut with a trilogy?

I’m writing a book and I’m at 90k words. I know it’s gonna be over 120k. I’m kinda nearing the end of it, and I have just now realised the book would be so much better as a trilogy. I could get more of the world building in since it’s a sci-fi/dystopian.

The problem is, it would be my debut novel. I know people are saying it’s hard to get a publisher who would take that risk, but I’m asking if it would be impossible. And I’m asking, how hard would it actually be?