I'd say anything that is reusing a lot designer is king to build the trim sheets or tilables. Any unique asset will profit from sculpting. That being said, nobody is stopping you from using designer generators, textures etc to texture your uniquely sculpted mesh
nothing stops you using both sculpt some bricks, bake heightmaps and use designer to lay the heightmaps out Designer is not well suited to creating very specific shapes - if you need one of those, use a tool that is well suited to the task and use designer to handle the bits that it is good at