how do stds even arise and why aren’t people more afraid of them

People just don’t seem to care. a girl i know had over ten sexual partners and she was willing to have unprotected sex. I said no. Surely she knows about the risks and that you can get stds and i have been super paranoid but then i read this article which was very informative and hilarious

https://www.google.com/amp/s/markmanson.net/std-guide/amp
here’s a funny part

“What’s never discussed is the actual prevalence of STDs, the realistic chance of catching these STDs, or what the experience of catching them would be like.

I still remember the night a girl I was dating told me that she had HPV. I felt like I was going to vomit. I immediately imagined that my penis had morphed into a giant tumor, shooting pellets of cancer into girls’ cervices. Or the time one of my best friends told me over the phone that he had what appeared to be a herpes breakout. I nearly cried for the guy. Holy shit. What was he going to do? No woman would ever date him again.”