Some background information on falling from high places:
The terminal velocity of a falling human is around 120 miles/hour and once that is reached, it doesn’t really matter how much higher a person is falling from. (There are exceptions to that but I will explain it after)
If a person can land in an area that spreads out the time of impact by even milliseconds it increases their chances of survival. The difference between landing in snow versus landing on some concrete. There is a pilot who served in WWII who survived a 20000 feet fall when he had to bail from his airplane without a parachute meaning it is possible given the correct conditions and some luck.
Coming back to the first point about height, if a person falls from a height of greater than 60000 feet there are two things that can potentially happen. Since the air is so thin at higher altitudes, the person could spin extremely fast and die because of the blood rushing to their head. Additionally, as they fall their blood could boil because of the lower atmospheric pressure.
So although it is rare, it is definitely possible to survive a fall from extremely high places.
Bringing this information back to this scene:
For a human to reach their terminal velocity it takes around 55 stories meaning that Ethan was far from this number. But this doesn’t mean he couldn't have taken serious damage which is why he was so hesitant to jump. Even a fall from 3 meters can cause spinal damage and a fall from 10 meters can causes far worse. Landing in the proper way is what gives a person the highest chance of survival. Ethan lands on his front which is not the best but he also has his arm out to cushion the fall. Since his speed was not that great, the concrete didn’t kill him and this was enough for him to get up and proceed. This scene seems to check out.