In 2011, I joined a company and one of the first things my manager asked was my chat email. I sent them my yahoo email. Few minutes later, everyone in the team had added me to their chat. My coworkers all used a different handle. There was AIM, facebook, google, yahoo, and some that I don't even remember. After a few months working at the job, I switched to Empathy on Ubuntu. I didn't have to let anyone know, I just contacted them directly from my new handle.
Chatting and the protocol that makes it possible was solved.
But today, I face a new challenge when I meet new people. They ask for my Snap, request my Instagram handle, or "Are you on messenger?" I don't use any of these platforms for chatting. They may request my presence on Facebook, WhatsApp, or some other obscure application that I am not aware of. The only way I can communicate with them is if I join whatever walled garden they are part of.
Interestingly, SMS remains the one sanctuary where we can communicate without the constraints of exclusive platforms. Yet, SMS remains under constant threat, with tech giants like Google casting a long shadow over its future.
Also as a bonus, I have a record of my chat history in every company I have worked for. It's great material if you are writing a book about work. But not so much since everyone switched to using Slack.