I'll "embrace it" when the authors stop writing "Old man! Old man!" all over the pages.
Yes ikr.
Also, sure irl age gaps that far aren’t actually rare, in fact, most of them even have appearances that doesn’t look that far apart.
But in these stories, it just has to be a girl that was sorta raised by the guy. There’s also the fact that the character could look younger just by shaving and the story will point that out, but leave it as it is just to sell the fact that the guy is old compared to the girl. Additionally, the design for the girl will surely be made to look young.
Even when it’s not the character himself saying he is old, sometimes he is given the role as being strong but acts like he should as an old man so he stays underestimated, and this will be the opportunity to write and have characters calling him out for being old.
It’s blatantly obvious that they’re really trying to show that he is old.