I’m in the same boat. Over the years I’ve dipped my toes in these waters only to pull back out immediately. But it looks as though things have advanced and I’ll really do it this time.
I’m about to try Jitsi (whose webpage says it does do desktop sharing BTW) and https://www.getonsip.com/ to provide *both* SIP and XMPP (I was scratching my head wondering which to go with, but Jitsi and getonsip support both).
I have many contacts in China and the Chinese version of Skype (actually called TOM) is open to govt monitoring 😯 Another reason to lose Skype.
If the Jitsi/getonsip (or similar combo) proves fairly simple, I’ll try to convince all my China contacts to make the switch by saying something like “Well now that Microsoft owns Skype, you soon won’t be able to use it on an iPhone/iPad!!11!!” Appeal to their aspirational side 😉