> I am not sure why it works so well here.

I'm guessing (since Norway and Sweden tends to be more similar than different) that Norway also have something similar to the Swedish "Marknadsföringslagen" ("The Marketing Act") that effectively outlaws companies from calling people who obviously don't want to be called. They quite literally get fines if they call people on these lists, hence the companies actively cross-reference against them.

I've worked in cold-calling telemarketing in both Sweden and Spain in my previous life, both companies I worked for were deadly afraid of accidentally calling people on these lists, and actively instructed employees to basically say "Sorry", hang up and flag the number if someone mentioned the name of the lists.