The other two do more damage with less reach. The light punch version (used here) reaches the furthest, but it does the least damage. At maximum range, it can look like a glitch or magic, but that's what's intended. It's well beyond the range at which anybody else in the game can throw. Something that's often overlooked about Zangief, but is core to his character, is just how far the screw piledriver reaches. Why is this particular move so revered? The shoryuken represents the most important guessing game in Street Fighter. The hadoken might be the cultural icon, but this move is game-defining, and so important that the fighting game community's key website and biggest tournament organization, Shoryuken, is named after it. If you let them frustrate you and jump in carelessly, you've already lost … and, most embarrassingly, to yourself. An opening will come, especially if they get too predictable about it. Frustrate them by refusing to play along. Block, and when it looks like your opponent wants you to jump over them, jump straight up instead. The way to deal with fireballs is, like many things in Street Fighter 5, patiently. Ken really shouldn't use fireballs up close, especially not in his big combos. This is applicable to Ken as well, but his recovery is much longer, so it's not really the game he wants to play.
Eventually, your opponent is going to want to jump in on you, at which point you've hopefully already recovered from throwing your hadoken and can counterattack.