Comparisons of the mass trend of the BCG stellar mass between the eRASS1 clusters and previous observational (left panel) and simulation-based (right panel) studies. In both panels, the mass trend is re-normalized at the pivotal redshift (z_piv = 0.35) using the best-fit M_⋆, BCG–M–z relation as in Eq. (24). The eRASS1 clusters are indicated by black stars, while previous studies are shown according to the lists to the right of each panel.