It makes perfect sense why everyone, sincere and fraudster alike, would want to promote SBF as a boy genius. It's a great marketing tool, it helps convince people who don't understand crypto to have faith in the product, and you also get someone who believes the spotlight should be on them, which is particularly useful for any fraudsters who would prefer to remain in the shadows.
Clearly SBF never questioned that praise (who would at the time?), and still is operating as though he were smarter and more special than everyone around him. The sad irony is it reveals that he's markedly less clever than most of the people he associates with. Caroline Ellison, at least from what I've seen, seems to have realized quite quickly that the smartest choice was to quickly realize she wasn't a brilliant as she had been told.