Just need to point out that BMI is bullshit for this kind of thing.
Offensive linemen are often the strongest guys on the team. They have bellies, but the weight is needed for leverage. They have to not only be able to block D linemen, but also push them around and make holes for the offense. Their hands and feet have to be quick as fuck. As already mentioned, they run pretty damn fast, too.
Size is a part of it, but size+quick feet?? Reading a defense in a split second and getting that 300+ mass to move in the next split second? That's elite. Not the same kind of elite as say a wide receiver. But elite. My ex was a DE (defensive line) and they had him gain like 50lbs to move to LT (offensive line). The game doesn't ALLOW for the size, it REQUIRES it, with minimal loss of overall athleticism. Try getting big enough and actually staying lean, at like 6'5"-6'7" height. Not gonna happen.
As far as the amount of action...considering a lot of pro guys have some level of dementia by the time they are 45, I think it's reaching to call it a pussy sport. They get knocked around pretty badly. I don't think it's accurate to measure athleticism only by stamina or how long you can maintain constant motion, either.