Pretty much all girls can get a Chad or Chadlite to bang them. Therefore, if you don’t fall into those categories, you really don’t have much to induce a girl to love you.
Remember, love is about lacking other options. If you’re the most attractive guy she can get, then that’s a basis for love. But what if you’re not? Then all you have are your betabuxx; which turns it into a bidding war, because any guy with more money can outbid you. Also, at any rate, she’ll always be wanting some alpha fuxx to complement your beta buxx.
But if there was pair bonding, then that’s one thing you have that does make you special, that the next guy can’t have with her. Since pair bonding isn’t conditioned on beta buxx, it essentially falls into the same category as alpha fuxx. In a way, it’s actually better than alpha fuxx, because there can be another guy who can be more alpha than you, but there’s only one guy who’s her first.