A lot of it has to do with the platings on component leads/terminations. Within the last 10 years it's become clear just how well component manufacturers have d

A lot of it has to do with the platings on component leads/terminations. Within the last 10 years it's become clear just how well component manufacturers have dialed things in. They had to go pretty far to do that, though. I know the amounts used are miniscule, but it still amazes me that cheap commodity ICs have leadframes plated with palladium and gold, and dirt cheap resistors have ruthenium in them. (All very, very expensive noble metals!)