Glad you liked the post, and I'm glad to hear that you have better music tastes than most of these youngsters. 😉

Your comments actually tore open the crux of the book, which I only tapdanced around in the review because going deeper would give spoilers. With that said...

SPOILER ALERT!!

I think the reason why people view relationships between young people and older people negatively is that psychologically, young people are not mature enough to deal with certain decisions or circumstances and are in fact prone to manipulation.

Right. The main character's central conflict is that everyone tells her this is the case and she insists otherwise, and her challenge to the world would be best summed up as if I'm enough of an adult to be held accountable for my own decisions,and enough of an adult to be told I'm expected to stand on my own with no help from others, then how can you say I'm not enough of an adult to make my own decisions about my own relationships? Her insistence that she has made her own choices even while the world around her tells her "you are being manipulated" is the main theme of the book's third act.
She does point out the vulnerability of the younger party in such relationships. In fact this is a key factor that causes both of the main characters to try (unsuccessfully) to show restraint throughout the first two acts. In the end though, a romance novel is going to do what a romance novel is going to do, and they fly into each other's arms.
It's worth pointing out that for MOST of the book (with the exception of two scenes which I guess would be entitled "you write the way you dance" and "Dr. Sun and Madame Soong") she's the one who pursues the male-lead, rather than the other way around. Though this isn't a hard-and-fast rule throughout; the author is pretty good about not making any character completely monolithic.

I don't usually like these kinds of stories because they tend to romanticise these types of relationships or situations, which are delicate.

O'Brie is kind of... of two minds about this. In steamier moments she definitely fetishizes it (his term of endearment for her is "young lady," and the words "good girl" carry a definite subtext), and it can't be denied that one of the things she is drawn to is his age and experience. But both characters spend a lot of pages asking themselves "is this really the right move?" I guess the best way I can put it is that she doesn't romanticize it as a norm, but she definitely portrays it as the right ending for them.
But then, you know, a love story where that's not the case would be kind of pointless, wouldn't it?
As far as "does she romanticize these kinds of relationships," she doesn't portray it as an ideal. Even the main character's best friend (whose key role in the story seems to be giving terrible advice that leads to trouble, which is a fairly realistic portrayal of a high schooler's best friend) spends most of the book waffling between "ooh, that's scandalous" and "girl, are you crazy?" But the book definitely forces the reader to sit down and listen to the female lead's challenge of if I'm an adult, why is it anyone else's busines? Kat's lament when their relationship is discovered (the quote I used at the beginning of the review) is probably where the author puts that in the starkest terms.

Anyway, I enjoyed reading it. I would probably have some questions if my daughter's teacher put it on the required reading list though.
Then again, both of those can be said for ACOTAR, so... shrug