Did I watch the same show as everyone else singing their praises about this? Or did I watch a different version of the show that was badly written, badly acted and where the main couple both as a couple and as individuals separately were annoying AF?

I wanted to start with positives, but I genuinely could not come up with one. I tried.
Now onto what I didn't like. I don't normally notice these things but the color scheme was very bleak, so visually I already did not like it even before getting into the story. But not to worry: the story was bad as well; I didn't like the superpower aspect right down to the first scene and how it was handled; I didn't like that it took so unnecessarily long for her to take action, how she let the guy slap her, the way she talks under her breath, I generally don't like the way FL was written/portrayed, but more on that later. I hated the screeching gay character, that was so hideous, unnecessary and insulting. It's especially tone deaf to make a gay character so hysterical given that not too long ago homosexuality was considered a psychiatric disorder. I didn't like the casual mixing of a serial killer subplot with a romantic comedy, like why? Because it tries to do multiple things at once, the show doesn't do any of them well, and the story as a result feels hollow. Oh and it has poop jokes.
I didn't like the three main characters, I don't know if it is down to the writing, directing or acting, but this show has stained the actors for me, so much so that I don't want to watch anything they are in. I was watching Our Blooming Youth because I thought the story would be interesting and the only way I could do that was by skipping PHS scenes, but it turns out that that show is also badly written and I dropped it anyway.
Starting with FL; I realized the reason I dislike her so much is because she is the product of the fetishization of young girls; everything about her says teenager: from the way she dresses, her voice, the way she mumbles, her posture, the way she interacts with the men around her and they even give her a child's desk at the office. The ML is the stereotypical eccentric rich guy doing eccentric rich guy things, who again acts like a teenager and that is all there is to him. Both of these characters are uninteresting and I don't understand why they would fall in love, but then again I'm also not interested in why they've fallen in love. SML only exists so FL can project her fantasies onto him, also he has one facial expression throughout the show and that is of someone who is perpetually trying to work out a difficult equation.

Genuinely I don't understand the praise this show gets. It might be the worst thing I have ever seen and I have seen The Room, at least that was (unintentionally) funny.