Personally I think the Ort cloud isn’t a shell around our solar system but is just the standard stuff that exists in interstellar space.
If it exists, the every star should have one similar. We should be able to detect Oort Clouds around most every star we look at. Why should our sun be so unique?
The comets and other junk are leftovers from some far supernovae or other destructive processes out in the universe, like bugs on your windshield on the interstate.......................