In my experience, even after having made fully sure that they understand the risks involved, "the average person" will happily switch back to a walled garden IM platform the moment the next stupid feature comes in.

Last time it was the (I think Whatsapp?) feature that allows, when replying to a message with an attached picture, to highlight a portion of the attached picture. That's it. There was no network effect at this point whasoever. This pseudo-feature was enough for an adult person to decide to switch back to Whatsapp and fuck my and everyone's privacy. THEN the network effect kicks in in favor of Whatsapp, because of course Whatsapp is a walled garden, so everyone is forced to switch to Whatsapp.

I have seen this already happen several times network-wide and I will see it happen again. Non-walled garden IM networks are just set-up to lose.