You are right. If everyone merges early, the cars that could have been in that mile of unused lane, will instead be in the full lane, moving the entire queue b

You are right. If everyone merges early, the cars that could have been in that mile of unused lane, will instead be in the full lane, moving the entire queue backwards a mile, clogging up more exits and onramps, and making the jam worse. Use all available road, that's what it's there for.