My understanding as an outsider is that astrology, tarot, etc function as a shared vocabulary and mythology to communicate about mental health and life's troubles. I think for most people the occult elements are largely aesthetic.
Throughout history people have used occult aesthetics to create a heightened experience. Sometimes that can help you commit to the process and get more out of it. (And other times con artists use it to get you to let your guard down, c'est la vie.)
Personally it's not for me, but when I got to know people who were into it, and did some readings to humor them, it made sense to me.