The relative speed difference of 130km/h means you're closing in on the traffic in front of you at 36m/s. That doesn't sound like much but if you consider how long it takes from checking the mirror to changing lanes, that's often just not enough time. Numerous times I've had the situation where I checked the mirror and by the time I've changed lanes, some car almost rear ended me. Relative speed differences like that are just a recipe for disaster and the only way to fix that is to make the fast car go slower.