I worked with chainsaws for decades without any PPE and have a few small scars to show for it. The first job where chaps were required, I had a mishap that cut through 3 layers of Kevlar on my thigh. Three layers was the minimum requirement. My chaps had five layers.
The first job that mandated a chain brake, I put it to the test when the saw kicked back and almost took off my nose. All I can say is good thing for safety mandates!