Supernova (SN) cosmology is based on the assumption that the corrected luminosity of SN Ia would not evolve with redshift. Recently, age dating of early-type host galaxies (ETGs) from high-quality spectra has shown that this key assumption is most likely in serious error. It has been argued though that the age-Hubble residual (HR) correlation from ETGs is not confirmed from two independent age datasets measured from multi-band optical photometry of host galaxies of all morphological types. Here we show, however, that one of them is based on highly uncertain and inappropriate luminosity-weighted ages derived, in many cases, under serious template mismatch. The other dataset employs more reliable mass-weighted ages, but the statistical analysis involved is highly affected by “dilution bias”, severely underestimating both the slope and significance of the age-HR correlation. Surprisingly, when we apply regression analysis with a standard posterior sampling method to this dataset comprising a large sample of host galaxies, very significant (> 99.99%) correlation is obtained between the global population age and HR with the slope (-0.047 mag/Gyr) in excellent agreement with our previous spectroscopic result from ETGs. For the local age of the environment around the site of SN in a host galaxy, a similarly significant (> 99.96%) correlation is also obtained with an even steeper slope (-0.057 mag/Gyr) which is fully comparable to the observed dimming of SN with redshift. Therefore, the luminosity evolution stands up to scrutiny as a serious systematic bias that can mimic dark energy in SN cosmology.