I have always been in age gap relationships, of varying sizes.
First long term relationship - I was 16 and he was 21, everyone else thought that was weird, his family were disgusted, his friends called him a paedophile, etc.
Ex husband - I was 22 and he was 27 when we met, nobody batted an eye.
Current partner - I was 32 and he was 42, now 35 and 44. Nobody cares. In the slightest. His ex wife sometimes gives him the “cradle snatcher” routine but she’s an idiot, everyone else has ever even mentioned the age difference.
I think, whilst my differences have never been over 10 years, it’s actually more to do with the age you are when you meet. I was a child at 16, with a man who had a job and a child of his own. It is weird, and it’s not proper consent, there’s a definite imbalance. There’s no imbalance with my partner now, we’re both adults.
It’s the involvement of teenagers and very young adults that’s the issue.