Google Hangouts = the original chat+video product which was semi-popular, but never got huge traction and mindshare the way WhatsApp, Slack, the original Skype, or the newer FaceTime did. And now Zoom and Teams.
So Google realized it had to compete better against all of those, all of those being very separate communications channels with different priorities. Hangouts could never be an awesome focused product if it had to be all things to all people.
So the competitor to Facetime/WhatsApp/FB Messenger is Google Duo. It's originally phone-based and designed primarily for 1-1, though it supports small groups.
The competitor to Zoom and Teams is Google Meet. It's enterprise-based for huge meetings.
The competitor to Slack is Google Chat.
And Google Hangouts is this zombie product that used to do everything, but never as well as any of the competitors, and still has moderate consumer usage so they can't kill it, though I'm sure they're doing their best to figure out how to get people to migrate eventually without losing them to a competitor in the process.
So despite all the flak Google gets for a fragmented messaging ecosystem, it's driven by extremely valid market reasons.
And Google isn't a video communications platform, it's a company. With several platforms, serving several totally distinct markets.