Let me assure you that Deutsche Bahn also still operates about 500 mechanical signal boxes, about 100 are from pre-WW1. Not these fancy, modern electromechanical relays (which Deutsche Bahn of course also has).
You're underselling it. The ex oldest operating signal box in Hörlkofen was finally removed from service less than a year ago, 2025-12-12.
It entered service in 1899.