If John Wheeler is correct that we not only participate in bringing change to being in the world around us but also the far away and long ago by observing the Universe. Then it is the epiphenomenalist who will be cut by Occam's razor.
Schroedinger however believed that this issue will never be resolved by science. So we both might need to take our leaps of faith for a long time.
Wheeler's "self-observing universe" has long been abandoned by science metaphysics and philosophers of science in favor of more realist (or rather, less anti-realist) interpretations like the Copenhagen Interpretation and quantum decoherence. Wheeler's SOU was based on Wigner and Bohm's "consciousness causes collapse" interpretation, which is ultimately bad metaphysics. (In fact, nowadays it's called "quantum quackery.")
In fact the issue has already started to be resolved with quantum decoherence: the wave-function doesn't exist. It's only apparent. This was already guessed at by the Copenhagen interpretation, but we're starting to understand why.