So I just use WhatsApp.
Google's communication services are so complex and poorly defined I avoid them like the plague, always have. I just don't understand what app to use and how they all relate.
Doesn't matter, I always hit the wrong icon 50% of the time.
I bet they took the team from Microsoft responsible for ramming the Skype/Lync/Communicator/Skype4Business brands into the ground and brought them over. Remember when Groove used to be Sharepoint but now it's a music player from them?
Out of nowhere they started to update it again sometime in the latter part of last decade, it still has 2 panels in the configuration backend because they halfassed implementing the Material interface and didn't include all the features. Despite this I'm ride or die with it because there's nothing else on the market that gives you a fairly un-stealable number for free.
Oh and to continue the fragmentation, Google Voice for Workspace is a totally different product similar to Vonage Cloud. As has often been the case with their paid services for years, the free users generally get a better experience.
EDIT: I honestly think a big part of the reason this has stayed running is Bandwidth.com runs most of the show under the hood and that company knows what they're doing. Another Google service they ran was GOOG-411 when that existed.