Google is Shutting off Hangouts and Propelling Users to Chat
Google has reported its plan to switch Google Hangouts users over to Google Chat next year. It is also making Chat a free service alternately limiting it to Google Workspace (formerly G Suite) customers as it is today.

In the first half of 2021, Google will begin migrating everyone from Hangouts to Chat and it will automatically migrate Hangouts conversations, contacts and saved history.
It hasn't explained how it will accomplish the conversion for users of the free version of Hangouts, but says it will provide more certain guidance on what steps users need to take when it begins the transition process.
Google states that the advantage of using Chat is it's simplicity in planning with others on "goals and similar interests, sharing and collaborating on files, and assigning tasks to help keep everyone on the same page".
The future of Hangouts has been unknown for some time, with reports in 2018 that Google was working out to shut the service down in 2020 and focus on Meet, its video-conferencing product, and Chat.
Google reports that the migration from free Hangouts to the free Chat will take place step by step and that there will be a period when both co-exist. After all free users and Workspace customers have shifted to Chat, then Chat will be examined to have restored Hangouts.
Google has published a notification about the migration from Hangouts to Chat, which points to late 2021 as the timeframe for shutting off Hangouts, at least for Workspace customers but possibly also for Hangouts free users.
Eventually after Q2 2021, all Workspace customers will be migrated to the 'Chat Preferred' setting unless admins decide to opt out of that change. But the switch to talk Preferred is going to be forced on Workspace customers in late 2021 with no option for admins to cop out .
"We will fully replace classic Hangouts with Chat. There will be no choice to opt out at this stage," updates Google.
Google assures Workspace customers it will provide a minimum of four weeks notice on the Google Workspace Updates blog before each phase begins.
These two steps represent the final two of five steps in Google's Chat upgrade timeline.
It is reported in late 2021 "all remaining vintage Hangouts customers are going to be migrated to "Chat Preferred," which we'll fully replace classic Hangouts with Chat".