I cal it “The thing formerly known as Twitter.”, because it’s short and to the point.
Just like when Musk tries to explain one of his many lies, like why the self driving cars he promised would be ready in 2017 haven’t arrived yet.
Also it doesn’t really matter if we call it a failed banking app, or a failed video app, or a failed message app. All of those are true. But it’s shorter and easier to just call it “The thing formerly known as Twitter”. Then everybody knows what you are talking about.