I'm pretty sure they use that internally (when I was there Hangouts was used). However, Google work culture is (or at least was till fairly recently) centered around shared docs and email (automations send email with action buttons for example vs. hip companies were such things are fed into Slack). Hangouts was mostly used as a lightweight 1:1 or small group communication and resolving an issue. I imagine post-COVID the Slack-style Chat has gotten more use, but I'd bet Gmail is still at the center, not Chat.

while google chat seems not for enterprise use, right?