Shift in the best-fit estimation of cosmological parameters induced by neglecting magnification in our theoretical model. The values of the shift are expressed in units of the marginalised 1σ constraints. The blue histogram refers to the parameters estimated from the GCph alone analysis, and the orange histogram represents the shifts for the 3 × 2pt analysis GCph + WL + GGL. The red regions highlight shifts above 1σ in absolute value. The values of the shifts computed with the Fisher formalism cannot be trusted quantitatively in this region.