You don’t observe the photon or electron directly but only by effects of interactions with them. It is the same with wave collapse. In this case what you are observing is the difference in the state of a system before and after a measurement has been made on a system which is not in an eigenstate of the measurement. Before, the results of a measurement on this (non-eigen) state gives random results. Afterwards the result of a measurement on this state (now an eigenstate) is always same result as you got from the measurement which changed the state of the system. Of course you only see this by making many such measurements.
Frankly all of it, including electrons and photons as well as these wave functions can be considered mathematical constructs which we have invented to understand the results of measurements.
True… but I think more emphasis is needed to avoid misunderstanding what is being claimed.