sorry for the late reply!! tbh I’ve been into jjk for 3 years but most of the time I’m in my own safe space among skfs/skn fans, so I don’t know much about that side of the fandom but since I also read the manga, you’re definitely not mistaken.

I believe it’s a fandom’s headcanon that is so widespread to the point that some people confuse it with canon. it’s clear in the manga that the jujutsu tech financially provides Megumi and his sister in exchange for becoming a sorcerer, so it’s not like Gojo spoils him and his sister in that way. he’s not trying to become Megumi’s father or anything because otherwise Megumi would have thought of him differently than merely a teacher whom he owes his life to, and otherwise he would have regarded him as high as he did Tsumiki. And yet the fact is, the only one who managed to do that was Yuuji.

but it’s not like Gojo didn’t do anything; he helped him away from the Zenin clan and taught him to fight as a sorcerer. Gojo showed him a way to avoid him and his sister from going a poverty path and most likely the only adult who came to them at the right time. it’s not something to be taken lightly as well.