Why is personal protective equipment used?

To keep all your parts from being damaged. Eye protection should be used in case there is a possibility of getting something in your eyes that could cause damage to the structure. Gloves are used to prevent fingers being cut off. Respirators are used to keep your lungs from being scarred. Steel toed shoes are used to keep your toes from getting broken.

The whole point is to do the job without losing a part of your anatomy in the process. Personal protection can vary depending on the job, but in each case, it is important to have it. Some people would say that they are not used to products like those PPE and that they are very experienced with their jobs. Some of them gets lucky but not all of them walks away without any injuries or even fatalities. Prevention is better than having to deal with possible injuries you can obtain without those PPE.