I fully agree with the contention of Mighty God King that Betty Cooper is "motherfucking psycho bugfuck crazy." I've seen too many examples of her unhingedness (probably not a word) to be unaware of this. But I wanted to add an important point: in talking about how crazy Betty Cooper is, it should not be assumed that Veronica Lodge is not also crazy. Maybe she demonstrates her insanity in more socially-acceptable ways, plus she's wealthy, and the rich always get more of a pass for their eccentricity. But she's just as devoted as Betty to the stalking and terrorizing of Archie Andrews.
And as this story from the '60s proves (art by DeCarlo, script probably by Doyle), the two have this weird and kind of sick understanding: their "rivalry" will be set aside any time it looks like Archie might even look at another woman. They will then scare the woman away, either by using violence on Archie, or using extreme violence on the woman (including women he doesn't even know, let alone date). Only when they have guaranteed that he is too scared to touch another woman -- knowing what they will do to her -- do they go back to fighting amongst themselves.
So to the 60+ year-old questions: 1) "Why are two beautiful girls fighting over an idiot with a waffle on his head?" and 2) "Why doesn't Archie find someone he's compatible with instead of two women he's not fully compatible with?" The answers are:
1) Because they're both completely insane, 2) If he tried to start a serious relationship with someone else, that person would wind up like Pepper from Josie when Archie announced his intention to marry her. (That wasn't in the comics, but I'm assuming that's why Pepper disappeared. Her broken glasses were found floating in the local river.)
By the way, the first page of this story contains a trick for spotting a Frank Doyle story that I left out of my previous post: he never could let go of quoting certain songs that were popular in the '40s and '50s, even long after those songs were completely unfamiliar to any reader of the comic. "You Always Hurt the One You Love" was the song he quoted second-most-frequently, behind "Too Young,", which he went on quoting into the '80s:
(Art: Bob Bolling) (Art: Dan DeCarlo)
In fact, my first introduction to the lyrics of many classic songs was this panel from Life With Archie in the '60s, consisting entirely of quotations from songs that were already unrecognizable to the Archie target demographic even then.
(Art: Bob White)