URP/HDRP - why different postprocessing systems?

Now that URP has support motion vectors and depth/normals textures, wouldn't it make sense for the two pipelines to share a common postprocessing system and effects?

Why can't we enable TAA or DLSS in URP, for example?

Or choose between 'cheaper/simpler bloom' and 'HD bloom' in either pipeline?

Or maybe even create custom render pass that works with both (or at least shares the same API)?

Being able to use more of the higher-end effects in URP would make URP more universal, and allow more scalability between platforms.

 

I think it's because HDRP uses compute shaders which they are trying to avoid on URP.