The real uses of tessellation are anything to do with texture/material driven displacement.
Being able to just slap on a crater decal and watch it displace the geometry to create a 3d depression, with correct shading and even collision would be the dream. Same with any other material, blending in brick/concrete/layered with chipped and cratered decals, all on a material one could just paint, preferably on a spline/blueprint based geometry would make world art incredibly fast, flexible, and varied.
Functionally seamless UV and tessellation has a lot of uses. UE5 lets new geometry pieces come online incredibly quickly, but building that base geometry into world art is still in the same place it’s been for years (or decades really, including other engines). Getting splines and tessellation towards the same hero tool status as nanite would be a huge boon.