I've had times where the right lane ends up being the fastest. On I-5 near Woodburn, OR, it's 3 lanes. So many drivers, including truckers, will often stay out of the right lane entirely to avoid being caught up in traffic coming on/off. Meanwhile, the left lane is going 5 mph under the limit because there's a left-lane camper somewhere miles ahead. So I can fly past everybody in the right lane because there's actually barely any traffic coming on/off and everybody is avoiding the right lane for no reason at all.
The section of I-5 between Portland and Salem is absolutely psychotic, and I have never been able to reason out exactly why. It consistently has a left lane jammed with angry people going at or below the speed limit, a fairly normal center lane filled with cruisers, and a mostly empty right lane with the occasional big rig and regular very-high-speed cars expressing their frustration with the left lane by going 25+ mph over the limit in the right lane.
I know that's what you basically just said. Just venting. The driver behavior in that section of freeway confounds me, and I do not know what the underlying cause is. It is otherwise an unremarkable bit of interstate like any other.
There are plenty of ramps on I5 and 205 that I merge to the left for because I know they will spill into the right and (when it exists) middle lanes. Because of how traffic also reacts to brake lights (some people brake too hard even when they have sufficient distance to let off the gas and coast to a slower speed) it seems like it ends up making my experience through those stretches a bit better.
Ultimately, any individual behaviour is largely irrelevant, it's what the whole mass of cars moving along does that affects things the most. Often you don't want to be the (significantly) odd one out regardless of the situation.
Would I love to see CHP or OHP fine every left lane trucker in the 'no trucks in left lane' zones? Hell yes, but until that happens, I understand the trucker behaviour.
What I really hate, however, is that plenty of people will cruise in the center lane but still not leave a decent gap between them and the car in front. They effectively turn a three lane freeway into two one-lane freeways by hobbling the ability of anyone else to switch lanes. The freeway moves way smoother when there is a modest, predictable speed differential between each lane so that people can find their way into the next lane over without having to force the issue.