1/11-12/2022 I drove home (Crestview, FL) from Paducah. The traffic on I-24 tween Paducah & Smashville was so heavy if I got out of the left lane to let an odd car pass (the traffic in the left lane was bumper to ditto @ 85mph so there weren't many leaving the left lane). The few times I did step to the right to let one by the inconsiderate sobs
wouldn't even leave me room to get back in the left lane even tho we'd been running 2gether for miles & miles.

In that instance, if the left lane is a continuous flow that I'm maintaining the speed of the car in front of me, and there's clearly no passing opportunities, it's pointless to leave the left lane.
I try to stick by keep right except to pass, though there's many instances where it's not reasonable to leave the left lane.
Best rule of thumb, try to maintain the flow of traffic in the left lane regardless of speed limit. Slowing down and impeding the flow is going to cause more issues than help, even if "legal". Yes, you are legally correct, but in reality, it's not helping. Move over when you can.