The 'tapping phones' gimmick strikes me as something that sounds cute but will become an annoying chore that one should be able to opt out of. Particularly given various unintended side effects -- I personally wouldn't want my connection to my deceased best friend to be subject to some decay feature on a social network. And either way, it's not the core feature that will draw users to the site If you want to differen…
Optimizing for time spent on the platform is exactly what results in the current social platforms. The idea that the platform itself should be appealing and not a tool to connect with each others is in itself toxic IMHO