Gas fraction for all central galaxies relative to their hosting halo mass (top) and their stellar mass (bottom) in cosmosTNG at z = 2. The annotations and markers are as in Fig. 7, bottom panel. The gas and stellar mass are calculated within twice the stellar half-mass radius. We see an increased drop and scatter for gas fractions above M_halo ≳ 10¹² M_⊙ and M_⋆ > 10^10.5 M_⊙, in line with changes in the M_⋆(M_halo) and sSFR(M_⋆) relations. Above these mass thresholds, cosmosTNG galaxies show a higher gas fraction on average.