The curling iron used to be one of the least glamorous objects in the bathroom. You plugged it in, hoped the barrel was hot enough, burned two fingers in the process, and more or less accepted whatever came out. Now it has a learning curve, a TikTok following, and in some cases, a waiting list. The tools themselves have changed, and so has the conversation around them. Hair health has become as consuming a conversation as skincare, and that’s changed what people expect from their tools. Everyone...