A photon that is released from the surface of a star 20 billion light-years from the Webb telescope hits the surface of the telescope's CCD in the same instant when it departed the star. That is because at the speed of light, time stands still. A neutrino can penetrate mass that would absorb a photon, but time does tick slowly for the neutrino. It has a smidgeon of mass, so it can not travel at light speed.