Because the science is so hard to do, the products are basically entertainment. If you think of it that way it's hard for me to get too upset -- when it's affordable.
Some products are flat out dangerous though, and regulation is scant.
When my MIL was dying of cancer eventually then sent her home and "prescribed" various homeopathic concoctions (German insurance covered all this). At first I was appalled but eventually realized that as there was nothing left to do for her, the homeopathic bottles of water were a form of palliative care: giving her a sense of agency. I came to realize that it was a kindness.
Wearing makeup is often less critical, but given how important appearance is in culture, literature, and stereotyping, providing a sense of agency can be of enormous psychological value.
Some products are flat out dangerous though, and regulation is scant.
When my MIL was dying of cancer eventually then sent her home and "prescribed" various homeopathic concoctions (German insurance covered all this). At first I was appalled but eventually realized that as there was nothing left to do for her, the homeopathic bottles of water were a form of palliative care: giving her a sense of agency. I came to realize that it was a kindness.
Wearing makeup is often less critical, but given how important appearance is in culture, literature, and stereotyping, providing a sense of agency can be of enormous psychological value.