Why don’t PE funds (or really any institution) use model generators?

Used a tool during my internship this summer where we input assumptions (tranche size, mark, fees, commitment/sell down timeline, revenue opportunities, etc.) to calculate whether or not committing capital was worth it for the firm. Is there not a tool where you can do the same for an LBO model, or really any type of model? The only obstacle I can think of is the complexity of certain business models, however, on a whole (and especially at funds that focus on a specific industry), I think it would work with minimal troubleshooting. My thought is that juniors could focus more on diligence/strengthening the investment thesis rather than actually building it out. I guess a follow up question is whether or not you usually build an LBO model from scratch or start with a precedent and/or generic template, in which case thats sort of the same thing however a more user friendly platform/interface could still be helpful.