Wait hold on its gone? I didn't really like it other than being the only decently easy cross platform video call app. But I just made a comment thinking it still existed.
I've always found hangouts to be rather laggy, for some reason. I don't know exactly what they did to their UX, but I think they must've blocked their animations until their network requests came through?
I don't even know what Google calling system I used last, but I don't think they need anything new. Google Duo was perfect, except for the small issue that nobody used it. Hopefully, they'll just rip the code out of Duo and stuff it into their RCS client.