Go find someone who uses Facebook Messenger and has never heard of Hacker News. Ask them if they care about interoperability.<p>They won&#x27;t understand the question. They have a FB app on their iPhone and facebook.com on their desktop, and they won&#x27;t understand what you mean.<p>If they want to message someone &quot;on another service&quot;, they&#x27;ll just use that other service.