There are 250+ fat bastards out there who can barely lift HALF their own weight, and 150lb guys who can bench 1.5x their weight.
Of course there are the super jacked lightweights who can lift an insane amount and the super slobs that can't lift shit. Under normal circumstances weight ratio absolutely plays a role in the bench press. I guess rex is just a super slob, but that's no surprise to anyone.
I see some guys 40+ year old guys at the gym putting up 2+ plates (225+) on a barbell and doing sets solo without a spotter like it's nothing. Rex is just very out of shape, that's all there is to it. IDK why people are acting like it's a horrible thing to say. Have I ever benched 225? No, but I'm also about 175 pounds and when I was benching regularly I was doing 205 without a spotter, so I was pretty close... and I'm not even strong compared to many guys I see at the gym (I'm more of a squat/deadlift kind of guy).
How is that so? Your chest muscles don't get that much stronger in everyday activity no matter how much weight you carry.
I can't give you the reasons why. My guess is that heavier people generally have a bigger frame, broader shoulders, things like that. Google bench press weight ratio.
All that means very little when it comes to the bench press, leg press and your point is very valid since just from having to move around your legs have to be strong enough to carry that weight, chest and arms don't follow that theory. Now if you are talking about guys who weight lift often I could see where the bigger frame, etc can improve the potential for higher weight lifting, but if you are talking about a smaller guy and a heavy guy that are complete novices in weightlifting, the bigger frame means nothing.
We're just going to have to agree to disagree on this one. Go find two specimens that meet your criteria and try your theory out.
Given he's gone the distance to have surgery and has the kind of access he has, you'd think he'd be lifting some weights to help maintain a better body composition.