If she did Onlyfans her content would be the exact same. It's just that the reputation of Onlyfans greatly increases sales simply cause of the belief that Onlyfans = sex work. You can't use that bait on Fanhouse, Fanfix, Patreon, etc, which is obviously going to greatly limit your sales.
None of these girls really want to do Onlyfans if they can avoid it and prefer to sell their Instagram pics on stuff like Fanfix which is basically Onlyfans Jr. Onlyfans still has a stigma no matter how mainstream it tries to be. Some family, friends, etc, will be like, "ew you do Onlyfans? You whore!" But the money is just so much better there because of all the sex workers on there so you can make the simps believe you will also get nude and fuck like they do. Which of course you will never do.
If you think about it, the worst thing a girl can do is get naked on Onlyfans cause she loses her value then. Her most money making potential is in teasing nudity and leading the simps on.