@daniel The big plus of #DeltaChat is that the infrastructure is already there. Infrastructure is a big part of the problem. And obviously using mail for that is only for people born before 2000.
Second is branding: When people hear #XMPP they hear 20 years of failure of implementing robust solutions both server-side and client-side. People just don't know that after 20 years there now are server and client solutions really working.