For most of the history of building, a used door was just a cheaper door. Nobody called reused building parts character; they called them economy, and bought them because new cost more.
The economics of secondhand
Reuse ran on that math for centuries. Materials were dear and labor was cheap, the reverse of now, so when a building came down its usable pieces went back into use. A carpenter pulled sound joists and sold them on. A mason knocked the mortar off old brick and stacked it for the next job. Doors, sash, hardware, and mantels changed hands secondhand because buying them new cost more than buying them used. What people paid for was the material, the fit, and the condition, not its age.
What survived, and why
That plainness decided what lasted. Parts easy to reuse got reused until they wore out or fashion turned against them; fragile, awkward, or unfashionable parts got thrown away. What sits in a salvage shop now is the residue of a long chain of practical calls, most of them made by people who would have laughed at the idea of collecting an old socket. Before paying a premium, price a good reproduction of the same part. Salvage is often still the cheaper one, and it is the part that already did the job.
People only started paying extra for age recently. Once factories stopped turning out solid-brass hardware, heavy cast fittings, and hand-poured glass, the old stock was the only stock left, and scarcity did the rest, turning the cheapest option into an uncommon one.
So a reclaimed part comes to you already used to being sold. It has changed hands before, probably more than once, and every time for the same plain reason: someone needed the part, and this one was cheaper than new.