@rysiek @m I've yet to see #Matrix be better than #IRC.
If you need "closed" group chats, consider @zulip as an alternative. OFC it doesn't do encryption, but that's not the focus of #Zulip.
Not shure if @delta does "#E2EE group chats" but I'm certain that if one needs security, E2EE and Group Chats are somewhat exclusionary as part of #OpSec, #InfoSec & #ComSec best-practises go.
- Tho OFC one can use #PGP/MIME and thus E2EE all messages to all recipients i.e. using #Thunderbird.
As for a "secure yet convenient solution" I can recommend #XMPP+#OMEMO with @monocles / #monoclesChat and @gajim / #Gajim...
@kkarhan @rysiek @m @zulip @delta @monocles @gajim Yes, Delta supports e2ee group chats.