A Canadian company, Blackberry has admitted defeat to other platforms by announcing that it will end consumer BlackBerry Messenger service on May 31st, 2019. It posted a FAQ page that provides more details about the shutdown. The shutdown doesn’t affect the enterprise version of BlackBerry Messenger which is a completely separate app.
BlackBerry stopped manufacturing its own phones a few years ago. It licensed its brand name to TCL which now makes Android-powered, BlackBerry-handsets.