The biggest barrier to using an app like this will be new users getting hold of sats/ecash.  Its a giant PITA and requires some good technical knowledge OR giving away a lot of personal data to an exchange/bank etc (which is annoying and time consuming as it is undesirable for privacy).  Keychat will never gain any users beyond bitcoin enthusiasts.  Even nostr struggles and thats literally free and easy! 

 We will be more optimistic because we believe that more and more people will own Bitcoin. 

 BTW, Keychat users can also use free relays, like the Damus relay.