Search for a business plan template and you get a blank document. That was useful when writing the prose was the hard part. It is not any more.
The hard part is the numbers. A lender turns to the projection first, and what they are checking takes about two minutes: does each sale make money, how many sales a month cover the fixed costs, what is the lowest the bank balance gets, and does the amount being asked for actually cover that hole. A plan that fails those four questions does not get read past them, however good the writing is.
So here the projection is arithmetic on your own figures, updating as you type, and the written sections are handed those figures as facts they must use and cannot invent. It also asks who will read the plan, because a bank and an investor want opposite things from the same business, and a plan that ignores the difference reads like a template.