Is it possible to make calls so that I know for sure that the subscriber is online, like in Jabberd?

Let me give you an example with Jabber. When I make a call, Jabber (conversation) immediately tells me whether the contact is online. In other messengers, like Matrix or Delta Chat, this feature doesn’t exist, and it’s very inconvenient. If I remember correctly, early versions of Delta Chat calls might have had this, but now it’s definitely gone. Is it possible to implement this somehow?

See Call status is sometimes inaccurate - #2 by WofWca.

No, that was never the case in Delta Chat.

Is the implementation of such functionality being considered? It seems Matrix has listened to user feedback regarding such calls.