The problem isn't the harem, but the way Yuriel treats the mans,like nothing more than objectives and toys, our mc despise that tipe of thinking,even so that she felt disgusted by how the person who was in the body before her treated everyone. In that way our protahonist depises the "heroine" and the "villan", because the 2 of them are manipulative bitches.
Its not that I disagree with you- (I do disagree with the idea that SHE has a harem. She doesn't, she makes sure to reject them all except our cutie, so im so happy, but i saw that some people in the comments expect a harem and thats-)
She has a LOT going on, but i think she genuinely sees kissing more than one person as cheating. Like- she's the type that would not flirt with more than one guy like yuriel does. Or at least, when yuriel does it, she reacts like "oh. It seems she isnt satisfied with just you Rettsel" or "stop being greedy"
And i think thats the attitude of someone who wont have a harem- at least i hope thats whats going to happen

She makes such a strong case against yuriel having a harem, so i'd feel so disappointed if she has one