That's just being conservative. If you don't have to spend money, you're saving! /s
(But seriously on some level, probably the tactic. Why spend state money when you can ignore and then plead for money from the Federal government? It's so perfectly grifty. Lives don't matter, only votes enough to stay in power.)
It turns out, automakers were actually using headlights that were dimmer than legally required and getting away with it for decades.