Standardized skewness $\gamma_{\langle p_\mathrm{T}\rangle}$ shown as a function of $\langle \mathrm{d}N_\mathrm{ch}/\mathrm{d}\eta\rangle_{|\eta|<0.5}^{1/3}$ in Pb--Pb collisions at $\sqrt{s_\mathrm{NN}}$ $=$ 5.02 TeV, Xe--Xe collisions at $\sqrt{s_\mathrm{NN}}$ $=$ 5.44 TeV, and pp collisions at $\sqrt{s}$ $=$ 5.02 TeV. The predictions from different event generators and hydrodynamic model calculations from \textsc{v-usphydro}  and MC-Glauber+MUSIC  are denoted by colored bands. The statistical (systematic) uncertainties are represented by vertical bars (boxes).