How to revert to Google Hangouts from Google Chat?

My close relative have a phone which have both Hangouts and Chat installed. Chat does not have integrated Voice and Video call function. IMO, Chat is significantly inferior than Hangouts. So I still prefer Hangouts over Chat to communicate. It used to be a blue banner that says "Hangouts is being replaced by Google Chat". Today, when trying to use Hangouts, it just say that Use Chat in Gmail. This is even after uninstalling Chat and reinstalling Hangouts from Play Store. There seems to be no way out of it. For the time being, it can still receive calls. But since I have no way to bypass that "Use Chat in Gmail" splash screen, I cannot do hangouts. Am I being force migrated? Is there a way to rollback?