it's not unlikely that they would have been keener to sabotage each others efforts rather than cooperating.
Ouch. Could be. I really think, in retrospect, they just needed a break from each other. I've been reading Keith Badman's "The Beatles Off The Record Volume 2: The Dream Is Over". John and Paul would have been happy to reunite after the whole Klein thing got settled. Ringo and George were more holdouts, perhaps because they got used to doing their own thing. But by 1975 even George was saying he wouldn't mind if they recorded together again (I know, not a stunning endorsement, but still).
Paul tells a funny story after this $30 million reunion offer was made. He and John had some trouble connecting, and he finally gets John on the phone and says, "Yeah?" And John says, "What? You called me!" and Paul said, "No, you called ME first, I'm just returning it." So they nattered about this and that for an hour or so, and hung up the phone, all happy, and Paul is thinking, "Damn! There was something I was supposed to talk to John about. Wonder what it was?" He'd
forgot about the $30 million offer. Which (Paul goes on to say) just showed how unimportant the money was to what the Beatles were. They had to get together because they wanted to do something musically, or it just wasn't going to happen.