with blairena, right from the beginning, from the moment we're introduced to them they're already feuding but you get the sense that they seem to owe each other a certain level of loyalty. even when you find out serena and nate, who is blair's long term boyfriend, slept together, you understand why blair is so upset. you get it. serena is her best friend and has been in her life forever, it is a massive betrayal. then as the show progresses, they both fuck up. they both hurt the other, they scheme and they tear each other down, but when it comes to it, they are there for each other, they apologise to each other and they hug it out. it feels genuine.
with veronica and betty, the writers try to do the same thing. they set up a love triangle with them and archie, but it doesn't quite work. yes, veronica is well aware of betty's crush on archie, she's informed by kevin almost immediately, but when she kisses archie, it doesn't really feel as big a betrayal. at that point, v and b have only known each other for days, v owes betty no loyalty, they're barely even friends at that point! i can understand betty feeling betrayed, but it just doesn't work in the way the writers want it to. then, as the show progresses, their friendship doesn't seem to grow organically (in my opinion). of course, the fact that they're constantly in life or death situations definitely plays a role in that, but afterwards it really just feels like veronica constantly giving and giving and giving, and betty takes and takes and she tears it apart! she makes multiple speeches where she insults veronica and she slut shames her and every other horrible thing she's said to her, the first time she kisses archie she and veronica have been "best friends" for two years, and i don't think we ever even see her apologise to veronica. the second time she kisses archie is four years since they've met (riverdale's timeline is never really clear, so im going off the seasons), she's had a full blown emotional affair with him, and still, we don't really see their friendship go through the pains of the betrayal. we only see the affair through the lens of their respective romantic relationships, and all we get is an "apology" and she's just, forgiven. how are we supposed to believe this friendship is so epic and so genuine if we don't even see veronica feel an inch of hurt by betty's betrayal? (yes I understand the whole genuine friendships should never be torn apart by a guy blah blah, but genuine friends would never have an affair with their friend's significant other, and if there is love there, there should, would be hurt too!) everytime their oh so great friendship should be challenged, it's over in a second, everything is forgiven and forgotten. who's buying that? no, I'm not saying they should be full out feuding/cat fighting like blair and serena, but tell me, if your friend did/said some of those things, are you going to tell me that you would forgive them in a split second just because they "had a reason"?