Well it is a self-insert just like 99% of romance
I just think the show is nothing too crazy, a 5 or 6/10 in my books. There are better romance out there but self-insert-wise, Gojo isn't too bad cuz he's autistic as fuck about his hobby. Also, romance manga always starts with fated encounters and people catching feelings for no reason. Exceptions are like, Angel Beats but that show is the definition of wasted potential (still liked the Otonashi storyline). Actually now that I think about it not really cuz it was literally fated for his heart to be donated to Kanade but at the same time how is Kanade there before Otonashi if he dies and then his heart is transplanted into Kanade? Just one of the many oversights that the goat Jun Maeda made because of fucking bullshit 12 episode AIWJHEBWIEJKH FUWEJH he's a 50 hours VN writer who the fuck thought it was a good idea.
Most romance manga i like is written by foids, but my favorite ones are written by males, they just speak to me in a way that a foid could never. Wataru Watari, author of oregairu, literally said "yeah I self-inserted into Hachiman and Zaimokuza because I was a lonely cynical chuunibyou in HS"; Akasaka Aka, author of love is war, said "I wanted to capture the feelings of high school romance even though I never experienced it myself". These chiggas are real as fuck. There are also some foid writers who are real as fuck like shiruka bakaudon, but there's less of em. Idk, I literally couldn't give less of a fuck about the sex, just give me some good fiction desu. There's so much out there that drawing any generalizations is very difficult. Tho I will always say this hobby was made principally for otaku males and incels, and foid and normie consoomers have invaded it beyond repair.
who cares about realism or not it's fiction desu. If you are dead-set on only male-written romance there's plenty around, just read Oregairu or Nagatoro or Love is War for instance. Spoiler, males can put out bad manga too.