I too believe parental consent should be required. I might have some different views from many. If your teen wants a piercing and you, the parent say no, they might get it done anyway, in a none safe way.
No, I'm not saying that we should always say yes, I'm only saying that through my own two daughters I've seen other teens get serious infections because mom and dad said no and they did it anyway

I said yes to multiple ear piercings, but I was clear I didn't agree and I didn't care for them. I also made them wait 12 months before saying yes. The deal was that if in 12 months they still wanted it, I would agree.