The one-and-dones probably weren't trying to make a career in the industry either.
I'm always impressed with the one-and-dones who do the pro amateur / casting / audition-type scenes.
You know the ones with the generic names that are tough to Google as not much will come up related to porn.
But their fuck skills are legit, and they're apparently just there as a bucket list item, or to pay off rent or a credit card bill.
I've seen a few scenes over the past 20 some years and thought - "She could easily be a mainstream actress or print / fashion model ... flawless face / body, etc."