This is why shearing is necessary (done compassionately, of course)

[Catherine]

That poor sheep. It must have seemed like a miracle when all that wool was clipped off. He looked so happy and stylish in his coat.
You are right, sheep do need to be sheered. Many animals need to be sheered. Obviously alpacas and llamas need sheering. So do many breeds of dogs. Dogs like poodles don't shed so they need to have their hair cut.  

I can't imagine what life was like for that sheep. It wasn't just carrying around all that wool. The wool was restricting the sheep's movements.  He must have been
pretty strong to survive that.

I guess the real issue is how the sheering is done. It can be done kindly and safely. When the sheering is part of the factory farming mindset it becomes much rougher, even cruel. Like everything to do with raising animals, when it is turned into a factory style operation all compassion and kindness to animals is lost.