And yes, as a sibling notes, Reese's peanut butter cups are actually alarmingly tasty, but.... as with any $1 chocolate bar, that's shitty HFCS-saturated chocolate and shitty palm-oil-laced peanut butter, with way too much sugar in it, so if you're too good for that, well, that's a credit to your tastebuds, good on ya.
So eat real chocolate with real peanut butter. Real peanut butter is nothing but peanuts and salt (it keeps well, but fresh-ground is better). Real chocolate, I trust you can figure out. Milk and dark are both good in this application.
Although, of course, peanuts are not true nuts (no more than macadamia or almond or walnut), they're nonetheless very nutty, and the effect is pretty similar to "almond bark", or hazelnuts with chocolate, or pecans and chocolate. And of course you can just eat peanuts with chocolate, an okay combination. But there's something weirdly perfect about peanut butter with chocolate, better than peanuts with chocolate.
But hey, although I'm not American, I am from America's hat, and I do like peanut butter in a few other formats too.
At one point in history, US farmers were encouraged to grow peanuts as a rotation crop to improve soil quality. That led to a glut of peanuts in the market, so people tried to find uses for them. Peanut butter was invented+ as one of these uses, and has been a staple of American diets ever since.
+Or promoted, I can’t remember
[0]: https://commons.wikimedia.org/wiki/File:Reeses-PB-Cups.jpg
Edit: yep, an online search seems to say that's an actual thing. I guess I'm part of the ten thousand today https://xkcd.com/1053/. I will never understand the US fascination for peanut butter.