@jaj @michal

It's a matter of taste.

Delta has a somewhat centralized development model, i.e. all client (have to) use the same underlying framework. Writing an independent client from scratch is almost impossible, I've heard.

In contrast, #Jabber/#XMPP is a diverse #ecosystem, grown over more than 27 years, applied to various use cases (even #IoT), an #openStandard by #IETF and #XSF.

The former is easier and faster to develop for, but also has limitations. I personally prefer the latter.