It is too late when they “try” because by that time all your friends will be using GoogleTalk because it was shiny and easy to use. And then you had to add your GoogleTalk account to your own jabber client because for some reason you could never really talk to people on their google talk accounts from your jabber.org account. And then google added some weird stuff to the protocol and you couldn’t connect to your talk account from your jabber client anymore. So you began using the Google Talk web client and told your remaining friends on jabber.org that they too should come use GoogleTalk because … and then Google officially defederates and those few people left talking to each other on jabber are finally alone. And then a few years later google announces it shuts down googletalk because they can. And xmpp is so dead that the fediverse invented a new chat called Matrix because jabber is burned beyond recognition.