This trope seems incredibly muddled, a full of examples that could be randomly transplanted from Sci-Fi Writers Have No Sense of Scale, Vague Age, Writers Cannot Do Math, Depending on the Artist, Comic-Book Time, and a bunch of other tropes. And if the idea is that writers lack the training to portray these things accurately, age should not be on there. Taking care of that in requires elementary math. Maybe examples should be restricted to actual physical inconsistencies.
It's too easy to pack an article like this full of 'justifications' but it bears mentioning that Wailord IS explicitly an extremely low-density pokémon (a living float), and it's not that strange for Ash to carry a 100-pound hippo on his head, when he once pulled a raft full of people with his teeth.
A great SF example is Star Trek. For all its forward-thinking brilliance, Gene Roddenberry never quite grasped how large the galaxy is, and this is shown in the basic description behind the "Warp Factor". Though it's been slightly (but not relevantly to the following) retconned, the basic concept of "Warp Factor" is that the "WF" is the WF cubed times the speed of light. So Warp 2 is 8x'c', Warp 3 is 27x 'c', and so forth. The original series Enterprise was supposed to be able to do Warp 6 (216xc) cruising, and peak at Warp 8 (512xc).
Now, that sounds fast, but in galactic terms, it's really not. In order to go just from Earth to the galactic center at warp 8 would take about 52 years. In order for events on the Starship Enterprise to take place in a "reasonable" time frame — less than two months between episodes, say (and usually much shorter) — the actual limit of time to go from place to place is rather small — a month at warp 6 is only 18ly, which is only a few stellar systems in any given direction. Even if there are stars fairly close, not all of them will be inhabitable or "interesting".
ST:Enterprise 1x07 — The Andorian Incident... this episode actually results in an internal consistency error. They state the star the "Vulcan Monastery" is orbiting. This is a real star, with a known location and distance from Earth. They also state roughly how long it has been since the ship left Earth. They have also defined what the ship's maximum warp is, about WF 5 (about 10ly per month). The distance from this known star to the Earth could barely be covered in the specified time frame at maximum warp, if they traveled in a straight line. Since there are four intervening episodes (the first was a "double" episode), with the Enterprise visiting a number of different worlds (including the Klingon home world, which places it ridiculously and improbably close to Earth) over that time, they hardly had any real chance to make it to the place in question in the time allotted. Someone didn't even do the basic math. They just pulled a name out of a local star chart and went with it.
Edited by OBloodyHell