I have this in my area, which was weird coming from actual big cities with way more dense traffic.
It's like the courtesy from the shared misery of, "We're all in this shit together" never got a chance. Instead people here seemingly never evolved beyond the "If I tailgate this one car, the 100 in front will disappear" phase.
When you're overtaking someone going slow, but they speed up next to you, so you're stuck now and will miss the exit. Just pretend they were probably lonely and just needed someone next to them for a while.
