In some ways, DeFi still feels like a solution in search of a problem.  For most people, it doesn't serve a real-world use case yet.  Which is why it's primarily used as a buzzword to peddle scam tokens and fleece the gullible at the moment.  Conceptually, it's a fine idea, but I'm certain there's a long road ahead before people really need this technology.  I wouldn't say it has "failed", just that it hasn't discovered its true purpose yet.