Google ended up with a bunch of chat apps because the culture promotes building new over keeping things running.
The first chat was basically an XMPP service. It was decent, it federated outside of Google, it was fully functional. It even supported group channels (XMPP conferences) internally. But I don't think that was ever exposed to the public.
Then Hangouts was created. It was, per usual at Gooogle, a ground-up rewrite. IIRC not the same team. So they spent at least a couple years playing catch up to get feature parity with the XMPP chat. Worse, Hangouts was one of the first services to suffer from strict team-created "Personas" design philosophy. Any time anyone would complain about a feature, or miss-feature, it was flatly ignored because "You're not one of our Personas". It took years of complaints to get them to change their minds.
By the time Hangouts was good enough to fully replace the previous service it was now boring and people left the team for other new projects. Because maintenance won't get you promoted.
The other random chat services were basically experiential toys.
Now we have Meet, which is is likely another case of "Hangouts is unmaintainable tech, we need to re-write it". Years of getting up to feature parity. And miss-features that won't get fixed.
Yea, it was great. But it was more lack of maintenance than anything. The original chat devs were passionate about open federation. The new devs were not.
Add to that it was a big source of spam that nobody wanted to deal with.
Apparently the team tried really hard to get more companies on board with opening up federation. But I think the only "major" service that did was what was left of AOL.
The first chat was basically an XMPP service. It was decent, it federated outside of Google, it was fully functional. It even supported group channels (XMPP conferences) internally. But I don't think that was ever exposed to the public.
Then Hangouts was created. It was, per usual at Gooogle, a ground-up rewrite. IIRC not the same team. So they spent at least a couple years playing catch up to get feature parity with the XMPP chat. Worse, Hangouts was one of the first services to suffer from strict team-created "Personas" design philosophy. Any time anyone would complain about a feature, or miss-feature, it was flatly ignored because "You're not one of our Personas". It took years of complaints to get them to change their minds.
By the time Hangouts was good enough to fully replace the previous service it was now boring and people left the team for other new projects. Because maintenance won't get you promoted.
The other random chat services were basically experiential toys.
Now we have Meet, which is is likely another case of "Hangouts is unmaintainable tech, we need to re-write it". Years of getting up to feature parity. And miss-features that won't get fixed.