I'm fifty-eight, and I've been a full-time writer for thirty-two years. I couldn't turn that into a full page bio if I were being paid five bucks per word. Nor would I try.
Publishers only care about bios if something really important is contained therein. Otherwise, a long bio can only harm you.
Good grief, the average person has nothing to put into a bio that is worth as much as a sheet of paper.
Agents often ask for things that no publisher I've worked with ever wanted. I have had publishers ask for a bio, but they always stipulated that it should be no more than fifty words, and just the brief facts, thank you.
As an editor, my eyes would glaze over with a full page bio, unless the bio said the writer had already won a Nobel, a Congressional Medal of Honor, and had been abducted by aliens.
A bio is a place where if you have nothing to say, don't say it. Never write a long bio just because an agent wants you to. A really good one takes on paragraph. A bad one, which means nothing really pertinent to say, should be no length at all.