I think #XMPP has a relatively clear and achievable path to drastically reduce the amount of metadata, but I’m increasingly worried that it is not going to move the needle in terms of adoption.
For 99.99% of people, the only relevant feature for an instant messenger is simply 'Are my friends using it?' The other 0.01% are equally divided between people who already use XMPP and don’t mind the metadata, and people who won’t use it anyway.