After learning a bit about HEMA...
Also, two handed weapons such as longswords or Dane axes need less strength and conditioning to use effectively than sabres or rapiers do, but one handed weapons generally have a better effective reach.
WHat a fucking piece of opinion. An axe need less strength than a sabre and rapier... Sure.
A two handed sword or axe has (wait for it) two hands on it that allow you to apply leverage onto the weapon. Most two handed weapons don't weigh a lot, otherwise they wouldn't move quickly enough. A Dane axe is a big stick with a narrow axe head on the top, it weighs between 2 and 4 lbs. A two-handed longsword weighs about 2.5lbs. A Zweihander weighs about 3.5-5lbs. All of these have two hands on the hilt and have guards that allow you to recover by holding the mass of the weapon close to your body.
A rapier is not a smallsword, it's a big, heavy thing with a very long blade and a heavy, complex hilt. A rapier weighs about 2.2lbs but is used in one hand, and is held out in front of you in a way that an axe generally isn't, as the rapier isn't used to defend in the same way. Also, some rapier stances are pretty uncomfortable and put far more strain on the knees and hips than the standard longsword stance.
TL;DR Its far more physically demanding to use a rapier than a Dane axe.