I always remind myself that way back then .... if you happened to cut yourself badly, there was a high likelihood that you could lose a limb or die from infection. They had treatments for stuff and they could be careful but all you needed was a chance infection (that is easily protected against today) and you could end up severely affecting your life or dying.
Even just a prick from a thorn while outside could give you tetanus, which was a super shitty way to die. People’s muscles spasmed so hard they could literally break their own bones.
But drilling a hole in your head did solve some other problems like brain swelling, so without knowing better and having no alternatives, I could see why one would try