Around here, at full-serve places, they take your credit card
and run it through the 'pay at pump' reader. But then since they're
to dad-gummed lazy to make another trip all the way back to the
driver's side, they leave the card stuck in the reader until the
transaction is finished and they bring you your receipt.

Quite annoying.

I often will get out and retrieve my card--- saves watching it
the whole time.

Once when I did this, the kid didn't see me do it, and asked me
"Did I already give you your card back?" after he didn't find it
sitting in the pump.

His eyes got wide.

So I said "No you didn't give it back to me, but I went and got it.
Since you didn't know what happened to it that means somebody else
could also have got it. I suggest you give people their cards back
right away."