In the UK it goes lanes 1, 2, 3. You stay in lane 1. Lane 2 and 3 are for passing only.
You will often see members of the lane 2 owners club just cruising along in lane 2 but this effectively closes lane 1 (undertaking is illegal and very unsafe).
Sitting in lane 3 closes the entire motorway.
I agree there is a speed limit. But the law says you cannot just sit in lane 2 or 3 if you are not overtaking someone. They even updated the law recently. If you hog lane 2 or 3 the police can report you and the penalty is 3 points and ยฃ100 fine
People who sit in lane 3 at 69mph are breaking the law and likely to cause an accident by forcing people to pass on the wrong side out of frustration (yes illegal but they will do it) and this is why they are over taking lanes, not just cruising lanes.
Never be the reason someone else does something stupid on the road. Always do the safest thing.