The difference between a guy cutting through a girder or a car with a single swipe (which he does all of the time, or equivalents), and lifting/benching even multiple thousands of times is like a difference of a magnitude of thousands. One is a level of exaggeration; one is so far beyond impossible that it's laughable.
It comes from the whole "super awesome ninjas can slice through anything via skills" trope, but is taken to ridiculous levels beyond that with Wolverine. As a comparison, even though it's really stupid silly with someone like Raiden in Metal Gear Rising, he, at least, is combining low end Class 100 strength, very supersonic swinging speed, a fully metal body (so that the path of least resistance isn't flesh and skin), and blades that have something going on outside of just being a hard, strong blade. And it's still silly. Wolverine has none of that and regularly accomplishes the same thing (and Cap to a lesser extent).