Matter evolution in large-scale structures. Left panel: evolution of the baryonic mass fraction f_b in halos (yellow), filaments (cyan), and voids (purple) as a function of redshift in TNG300-1 (solid lines) compared to the results of Artale et al. (2022, dashed lines). For halos, the solid and dashed lines overlap with each other. Right panel: evolution of the total mean electron density ⟨n_e⟩ in TNG300-1 (grey line), and in each type of LSS (coloured lines), as a function of redshift.