Since we all can be considered 'inhuman' in a way, being able to use magic and such we can do some inhuman feats like survive much higher levels of strain than compared to reality. Gravity would be normal, but our bodies are not as much. Can you be penalized for moving too far or landing too hard? Obviously there is a limit, you can't just plummet 40 feet into the ground and walk it off like spider-man but can your body survive being smacked by a bull and thrown 10 meters across the ground before being trampled? Yes most likely. 

I think the easiest way to discuss this is breaking it down into sections. For basic mobility-based skills people should think "is my ability meant to disengage/escape so I can't be attacked or is this ability meant for me to engage with." Splitting it into those two different aspects matters because its much easier to run straight into an enemy than it is to simply run away from one, like Batman for example. He often is seen literally leaping into the enemy or coming out of nowhere with a surprise attack but when he decides to run away, he's required to use a smoke bomb or a distraction to conceal his escape. So when one is making their ability they should keep in mind the abilities MAIN purpose, but this is all subject to a lot of "ifs" and a player should be able to their abilities as they see fit. 

I agree that such a massive gap closer is unnecessary really, 20 meters would be considered 'out of the fight' to me unless you're a long range-based class like long bowman or sniper. I think people should drop defining the actual distance they move and focus more on HOW exactly they move. For instance a teleport spell by a mage should require a casting time, making it slower than actually moving at the start but being able to appear anywhere instantaneously would beat out most other classes' in a long distance whereas an assassin who would have some sort of flashstep/shadowstep spell would be able to instantly use it and disengage at that very moment but be forced to scale time with distance, going X amount of feet would take Z amount of time thus not being as instantaneous as a teleport. One should also take into account your character's physiology, a meaty knight in armor should barely be able to pull off a combat roll while a mage in cloth armor should be able to tumble, fumble, bumble and bump as they please.

tl;dr - A logical gap closer should be well, logical. You shouldn't be able to traverse an entire area in a single second and your ability should be clearly defined on its requirements and limits. Distance should be relative to your situation/level of skill.

Did that help?