Well, if i think about the built in poly modelling in UE 4.25 upwards, then how would you give those models curvature, that you built directly here in UE? Would you need to export them to an external program for unwarpping and then baking, then re-import?
I know, that their modelling tools are in an very early stage and nowhere as good, as others, but they start becoming a thing and will most likely improve over time… but their models need materials too, and building such stuff in -engine and then being forced to go to external tools for UVs and baking the necessary masks seems a little bit counterproductive 