Users can control who joins the secure group chats by requiring admin approval when a new join request is created, so the host can approve or decline them.
Nice to see such chats also have features like raising a hand button, emoji reactions, enhanced desktop call views, microphone and camera muting, switching video source, etc.
And it is cross-platform too, so this should make it really easy for everyone to use. What with Telegram defaulting to no E2EE and WhatsApp leaking metadata like a sieve, Signal has become an attractive private and secure option for most users. Yes I know all about Session, Threema and SimpleX (and I use all three) but I have no friends using them, so they are not yet a mainstream option really.