There is no NTR without love. SAO is a popular NTR target because it wants to be a romance story but at least in the anime version the other girls keep having harem shenanigans. Damn studio not believing their viewers do not want harems. Like having harem appeal without being a harem.
If this is with a true harem show like To-Love-Ru then I doubt the feelings of NTR would as strong since Rito did not have such a strong feelings for any of the girls like Kirito and Asuna.
There is no NTR without love. SAO is a popular NTR target because it wants to be a romance story but at least in the anime version the other girls keep having harem shenanigans. Damn studio not believing their viewers do not want harems. Like having harem appeal without being a harem.
If this is with a true harem show like To-Love-Ru then I doubt the feelings of NTR would as strong since Rito did not have such a strong feelings for any of the girls like Kirito and Asuna.
Yeah, even if the love is one-sided, you can still evoke the emotional essence of NTR, although it may not strictly align with the conventional notion of cheating or a partner being stolen.
Regarding the harem aspect, I also agree. While it's not impossible, something like Mushoku Tensei could potentially function as NTR, but it's undoubtedly more challenging to execute compared to a monogamous relationship.
I mean, I have seen that critic countless times about the anime, but I never found it particularly true? At best the anime had the girls be a bit more cheeky or blatant at some parts, but never directly contradicted anything of the novels, funnily enough. For all that the 'pure' SAO fans insist that the other girls never romantically loved Kirito or that they got over it, as a reader of the novels I can say that they all DID, Sinon being the only one that maybe always stayed mostly platonic, and Sortiliena too if we count less relevant characters. For all that some fans wanna 'blame the anime', you can find countless minor scenes, sidestories, or extra material where the girls make it blatant they're all into him, Silica, Lisbeth, and Suguha have quite a few of these, and Ronye never even once tried to tone herself down. And the less we say about the mess with Alice the better XD The author unironically suddenly trying to backpedal and tone down their blatantness in the latest novel-only (So far) arc doesn't make this any less true
The difference is, they swallow their feelings and are legit happy for the main couple and support them in any way they can, not because they love Kirito but because they genuinely see both as great friends, but both things aren't mutually exclusive XP
To Love-Ru actually honestly counts more as NTR in my eyes because for SAO you can only 'really' NTR Asuna if you wanna be blunt, but for TLR a lot of the heroines count more than any of the non-Asuna SAO girls being stolen because Rito himself not only has accepted blatantly onscreen he liked Lala and Haruna (Who BOTH like him back), even if he never got together with them, but has actually had many scenes of blatant attraction and affection with most of the side-heroines, even if they also never put it beyond a certain point, there IS legit something there to 'steal' that's even mutual to a degree. Kirito meanwhile, while a bit of a troll or too friendly at times, never has shown any sort of real interest in the other girls.
Also, funnily enough, I actually find the SAO AU that actually is more blatant and Harem-like (The SAO Gameverse from the console/PC games) to feel better written than Canon SAO, and would probably think fits better for NTR of the series, but almost nobody really knows that one exists because it's extremely unpopular thanks to most of the fandom hating it for that exact reason XD