With proper technique, there shouldn't be a need to protect your wrist from the kettlebell however in the process of learning the kettlebell could slam your wrist and make it a bit uncomfortable (Clean & Snatch)
So that's why we recommend using wrist bands for beginners so they don't get any discomfort and start lifting more confidently until they get to proper technique
On the other hand for veterans that are lifting very heavy kettlebells, it can be uncomfortable on the skin just the pressure of the weightÂ
That's why we also recommend wrist bands for heavy kettlebell lifters