Paid for by people, not advertisers
WhatsApp is owned by Facebook, which translates your attention and data into ad revenue. As you probably know, that business model results in some complicated compromises.
Cocoon is different: people pay directly for the service. After a 30-day free trial, one member of a Cocoon “sponsors” it for their entire group. This allows Cocoon to stay ad-free and never compromise your data or privacy.