But they're not. Zipper merges might be the efficient thing to do, but here everyone is taught to merge early so the guy doing 70 km/h in the empty lane when the speed limit is 50 and then demanding to merge is generally seen as an asshole by everyone else, especially because those people usually don't wait for you to make room either, they often just start merging into other cars knowing someone will hit the brakes.

Except people do it anyway, I'm surprised so many people are trying to pretend they've never seen this.

Traffic isn't some collective consciousness thing that moves like a well-oiled machine. People are selfish and do what they think is to their best advantage, even if it causes the overall traffic conditions to be worse.