tl;dr: after pushing rcs so hard for years, killing hangouts well after forgetting about it, & hiding it from gmail, google now wants you to use its (and google allo’s) successor, google chat.
It’s really hard to fathom how Google’s decision makers don’t understand that in addition to being confusing, their failure to settle on one messaging app makes them look stupid and flaky in the eyes of average users. This isn’t some niche app for specialists that Google can get away with killing because the user base is relatively small. The general public uses instant messaging all day every day, and after having Google pull the football away two or three times, they’re just going to decide to use something that’s going to stick around instead.