Distribution of stellar masses (M_*) and SFRs for galaxies at z = 1 as predicted by the TNG300 hydrodynamic simulation (‘DESI-TNG’, left panel) and by the L-Galaxies semi-analytic galaxy formation model (‘DESI-SAM’, right panel). Our mock DESI samples are defined by selection criteria for M_*, SFRs, and the main sequence (similar to a cut in the sSFR), as indicated by solid lines (see Fig. 5 of Yuan et al. 2023 for a crossmatch between observed DESI and COSMOS galaxies). Note that the units for stellar mass are M_⊙ (without the h factor). The fraction of selected galaxies for such samples is shown in a grey scale.