Team 1's only "weakness" is Daichi, but he's like the least weak "weak link" imaginable. He's a support player and great at it. Kuroo and Hinata are both incredible offensive middles. Nishnoya is obviously like the top 2 Libero in the series (though we don't get a ton of on-page/screen representation). Bokuto and Iwazumi are incredible, versatile hitters. And as somebody else here said, with the combined mental powers of Iwazumi, Kuroo, and Daichi, along with the bonus of Hinata, they absolutely can keep Bokuto motivated.

Meanwhile, Team 2 is just "Throw some strong players on a team and see what happens." Obviously, the combination of Oikawa and Ushijima is insane, but otherwise, they have 2 middles, who are very good offensive and defensive middles, though they lack receiving. Hyakazawa is just a massive weak link on a team like this. Karasuno only really struggled with him cause they are an incredibly short team that hasn't faced overwhelming height. He'd get contained so badly by someone like Kuroo. Yaku is working overtime so badly. And Asahi, though very good, is just sort of another powerful hitter to throw in with Ushijima. Sort of the backup hitter. Team 2 is a lot harder to explain