「It happened because there were only five engineers in the Nothing mobile team, and due to this, Nothing OS-related work was outsourced. As of now, around 100 people are part of Nothing’s software team, and the Android 13 beta was completely in-house.」
https://www.smartprix.com/bytes/nothing-phone-2-confirmed-officially-pei-to-focus-on-us-market-more/

Smartprix

Nothing Phone 2 confirmed officially - Smartprix

Nothing Phone (2) will be a more premium variant that its predecessor and Pei will focus on making it US-centric.