You are sort of implying that measuring device is causing the wave to collapse, and hence the lack of an interference pattern. In that view, the universe is still a somewhat predictable entity i.e. it's not the conscious observer, but rather measuring instruments that are solely changing the photon's behavior. The casual coherent universe divorced of any souls observing it is maintained.

My sense is that the problem is more subtle than that. I quote a post from REDIT that gives some pause for thought.

We do not know how does it know, we just experimentaly proven that it knows. The experiment is delayed-choice quantum eraser experiment. It basicaly does double slit experiment with a trick to produce two photons out of one AFTER it gone through the slits.One photon travels to the detector where we observe or do not observe interference. The other photon travels to an array of detectors in which it has 50% chance to go to a detector that tells us which slit photon gone through, and 50% chance to go to a detector which erases that information and we no longer know which slit photon went.Surpise surprise when we knew which slit photono came through there were no interferance paterns, when we didnt interferance paterns emerged.Fun fact, the photons that told us which slit original photon came through hit sensors 8ns later than the one which generated paters. So the photon knew what we would know (or what we will not know(which slit it came through)) 8ns later. How? We do not quite know.Here is video explaining experiment:

https://www.youtube.com/watch?v=8ORLN_KwAgs