What's actually down there
Around here the culprit list has a local accent. In the county's older housing — the farmhouses out toward Esmont and Batesville, the mid-century streets near the city line — drains often run through original cast iron, whose rough interior snags what smooth plastic lets pass, and whose bottom half can rust away entirely while the top looks fine on camera. Under the county's mature oaks, maples, and poplars, roots work into every joint they can find; a line that clogs each spring is almost always a root problem wearing a grease costume. And in the newer subdivisions, the usual suspects are construction debris that never should have gone down and the wipes that packaging insists are flushable and physics insists are not.
The diagnosis question that matters first, though, is what your house drains to. A backup on an ACSA-sewered street points at the lateral or the main; the same backup on a septic system may be a full tank talking, and no amount of cable work empties a tank. Say which system you're on when you call and the visit starts with the right tool on the truck.