If everything is massless, everything travels at the speed of light, and nothing experiences any time (photons travel null geodesics with zero spacetime interval).
This is required to make Penrose's end state Conformal i.e. scale invariant, so that it can arbitrarily Cycle to a small scale to make a new Bing Bang Cosmology (CCC).
This is required to make Penrose's end state Conformal i.e. scale invariant, so that it can arbitrarily Cycle to a small scale to make a new Bing Bang Cosmology (CCC).