Relations between the cold gas and halo mass in our sample. The left panel shows M_gas vs. M₂₀₀, while the middle and right panels show ${\stackrel{\sim }{f}}_{\mathrm{gas}}$ as a function of M₂₀₀ and M_gas, respectively. The observations are colour-coded by the M_gas/M_* ratio. The plum dashed curve represents a gas mass equal to 4% of f_{bar, cosmic}, a median trend for our sample. All panels highlight the cosmological baryon fraction f_{bar, cosmic}. TNG50 (cyan) and Simba (orange) galaxies are also included. The bottom panels highlight with squares those galaxies with M_* lower than abundance-matching expectations by more than an order of magnitude.