Isn't all of this only useful if you know the information presented is correct?
Although the poster had a bus company business plan that includes actuarial analysis in his head and some spreadsheets so that bar appears to be sufficiently high.
In other words - If he was low skilled, AI would impress him. Now that he is high skilled, AI still impressed him.
In other words - AI improves on what a human can do.
Maybe we'll get to a point where we just trust everything we receive from these systems but I'm yet to meet a person who would fund a business solely on an LLMs generated business plans without being able to crosscheck them by someone trusted.