Full service gas stations have a long history of "old fashioned" card skimming - at least from my experience in New Jersey. My mother uses a separate credit card explicitly for gas stations because her credit card has been skimmed at NJ gas stations a half dozen times over the years.

Full service stations don't preclude a lack of terminal tampering. If the gas station closes at some point in time anyone can tamper with it after hours when it is unstaffed. Additionally, tampering can occur by criminals paying off employees to install skimmers.

Or an employee who covertly swipes your card with a reader that fits in his pocket before putting it through the pump

Didn't that partly change recently? When we were up in Oregon for the eclipse, one of the folks told us that you can now self pump between....some hour in the evening I can't recall and closing time.

Yeah, I lived in Bend for 3 years and miss that (among other things).