The buildings and the hardware
The mix of buildings in places like Conshohocken affects the hardware we see. You get older solid wood doors with mortise locks, prewar metal frames with rim cylinders, modern fiberglass or metal-clad doors with narrow latch faces, and a steady stream of multi-unit apartments that need keyed-alike or master-key systems. That variety changes the job: mortise locks require different parts and tools than bored cylindrical locks; old doors sometimes need strike-plate reinforcement or latch repairs because the frame has shifted; multi-family units demand key control and careful cylinder selection to avoid interference between units.