

It also sounds like they targeted you specifically while you were waiting in line. So not only did they only approach you about it when they could’ve asked anybody, they approached you in a place where it’s hard for you to just walk away. That’s sus to me, I think your instincts were right to not give them an in.
They’re pretty common on raw denim, especially if it’s unsanforized (i.e. not preshrunk). It’s basically because when jeans stretch and shrink zippers can look weird (have you ever gotten that weird pants boner around the zipper?). They also have a fade pattern that’s pretty classic. I dont think they’re any less convenient than a zipper once they’re broken in and you’re used to them.