Technically If you aren’t passing someone you are supposed to move over.Even if you are already speeding. It’s the law.
No it’s not enforced (except in colorado), but at the very least it’s common courtesy and you are disrupting the flow of traffic.
The right lane isn’t always open. And technically you aren’t supposed to pass on the right.
I chill in the left lane too…if no cars are behind me. If cars are behind me, that want to pass, I move over. Is just common courtesy.