I guess they realized muilti-backend keras is futile? I never liked the tf.keras apis and the docs always promosed multi backend but then I guess they were never able to deliver that without breaking keras 3 changes. And even now.... "Keras 3 includes a brand new distribution API, the keras.distribution namespace, currently implemented for the JAX backend (coming soon to the TensorFlow and PyTorch backends)". I don't believe it. They are too different to reconcile under 1 api. And even if you could, I dont really see the benefit. Torch and Flax have similar goals to Keras and are imo better.