See, here is the thing, Suguha actually was WAY more of a complex character than that, and while not as deeply as the novels the anime ALSO showed this, the issue is that basically nobody ever saw beyond "She likes her brother/cousin, this means she's another Imouto-Incest-Trope". Suguha literally has a realistic reaction to her feelings for Kazuto, she's suffering because she KNOWS he's in love with someone else and that under most circumstances he still would never see her as a woman, and she actively supports him, putting his happiness over her own rather than acting like a lovestruck sister cliche, hell, she gets her heart broken twice over trying to forget her feelings for him instead of being some bothersome cliche whose only trait is being in love with her brother to the point she's selfless at a borderline masochistic way, preferring to suffer repeatedly over forcing her feelings on him, even after she had a breakdown and actively was rejected she ended up understanding and rooting for his and Asuna's happiness regardless of her own feelings remaining, which is why I always liked her so much and lowkey made me a KiriSugu shipper, LOL
Of course, none of that matters for this game because her character was completely butchering to work in the NTR World setting and fall under NTR Tropes, so I had given up on seeing her in this game as anything but a source of good Suguha Hentai, which is why this sudden development was the most pleasant of surprises tbh XP As I said it reminds me of my favorite SAO H-doujin, where Suguha just goes full yandere and is fucking Kirito actively while he's in SAO having his honeymoon with Asuna, and when he finally logs out at the end of Aincrad she's there to greet him in the shadows with a full-on Yandere Face and a pregnant belly