I think the tapping phones feature -- for initial friend creation, not upkeep -- is THE killer feature of the app.
Do I want my teens on any social media apps? No.
Would I let them be on Facebook of 2006, when you were just connected to your friends and family, and not influencers and "the algorithm?" Sure! That and early Instagram were great ways to keep up with real-life friends.
If you made this as easy and pleasant to scroll through as 2011 Instagram was, with only-real friends allowed, I might even return to social media myself. It would beat having to WhatsApp my family my vacation photos.
(And heck, if this got big enough that celebrities were bumping phones with fans, heck, at least that's a more intentional connection than Insta forcing the latest wellness guru on my teen girl.)