Cluster number density per sky area (left) and comoving volume (right) against redshift. Red and purple lines refer to clusters detected using the eROMaPPer blind mode on the LS DR10 south and LS DR9 north, respectively, in the grz filter band combination. We restricted the samples to a reliable redshift range z_λ < z_vlim. The orange line refers to the eRASS1 clusters. A discontinuity at z_λ = 0.8 arises from the merging of the low-z-optimized and high-z-optimized eROMaPPer runs (see Sect. 4.1.1). A richness cut of λ_norm > 16 was applied only to the LS DR9 north and LS DR10 south catalogs. Volume densities for the SDSS DR8 and DES SVA catalogs were adopted from Rykoff et al. (2016) and for DES year 1, calculated assuming a survey area of 1437 deg² with uniform depth (see Table 4). The curves were normalized for a bin size of Δz = 0.05 and smoothed using a Gaussian kernel with a standard deviation of Δz = 0.02. The width of the lines corresponds to the Poissonian error for the same bin size, consistently as in Rykoff et al. (2016).