There's no exact reason why the Star Wars saga hasn't seen any Jedi use the Force to fly, though many fans believe it was because George Lucas didn't want his characters to be “too powerful”, and flying would have been a bit too much.
The reason why they never did it is because George Lucas never wanted to make his characters too powerful. Even though he showed them being powerful. Many would say that if a Force user were to use the Force to fly then they would leave themselves open to being unable to use the Force to defend themselves.
From a storytelling perspective, it also makes sense that Jedi can't fly. They're already powerful enough, and it would make numerous situations feel way too easy for them. Star Wars: The Phantom Menace already made this mistake by having Obi-Wan and Qui-Gon use their Force speed ability to run from droidekas.
Sustained flying would zap the Jedis' energy. They would have nothing left to fight the Dark Side of the Force.
Vader relies on the complex life support system of his suit to survive and it happens to be very vulnerable to electrical discharges. So, if Vader ever had unleashed Force lightning, there's a good chance it would've caused his suit to short circuit, thus, killing him.
And therein lies the answer. Sith specifically channel Force lightning using their hands. Seemingly, because Vader's hands are no longer there, he can't channel the dark side of the Force through them, meaning that he can't use Force lightning.
A Jedi does not act for personal power or wealth but seeks knowledge and enlightenment. A Jedi never acts from hatred, anger, fear, or aggression but acts when calm and at peace with the Force. Jedi are the guardians of peace in the galaxy. Jedi use the powers to defend and to protect, never to attack others.
Arguably, some of the rarest types of Jedi were the so-called Iron Knights. These are members of the Shards species - crystals with a brain of their own. They were Force-sensitive and all trained under the tutelage of Jedi Master Aqinos. The Shards had droid bodies, similar to that of General Grievous.
Although the 2002 film Star Wars: Episode II Attack of the Clones established that the Jedi Order members couldn't marry or have children, Star Wars creator George Lucas explained that despite their monastic regime, the Jedi were permitted to have sexual intercourse as long they didn't form attachments or possessive ...
So anyway, if you ever wondered why Obi-Wan Kenobi hated flying, here you go. It's all because of one moment years before TPM, where the autopilot of his ship took over and forced him to helplessly fly at high speeds through the narrow inner-workings of a massive ship. It seems that memory never really left him.
Grey Jedi don't exist since it's impossible to balance light and dark side.
Across the entire Star Wars whole galaxy, this means that only one in every ten trillion people is a Jedi.
Levitation
Although it's not often shown, Darth Vader is actually able to levitate himself against gravity and take himself anywhere he wants.
This is the most well-known of the Jedi rules. Love leads to attachment and attachment leads to strong emotions, which are the path to the Dark Side of the Force. Because of this, Jedi are forbidden to fall in love. This, of course, doesn't stop Anakin Skywalker from falling in love with Padmé.
He's living a pretty solitary life, he can't use the force. So, in a way, he's lost his faith. It's like someone that has stepped away from their religion.
#1 – Yoda. Yoda is widely considered to be the greatest Jedi of all time, and with good reason. He is a master of the Force, a skilled warrior, and has an unmatched wisdom that comes from centuries of experience.
Yoda. Yoda was a wise, experienced, and powerful Grand Master of the Jedi of an unknown species and the oldest known prophet in existence (having lived at least 900 years), considered the wisest and most powerful Jedi Master within the Star Wars universe.
Although the 2002 film Star Wars: Episode II Attack of the Clones established that the Jedi Order members could not marry or have children, Star Wars creator George Lucas explained that despite their monastic regime, the Jedi were permitted to have sexual intercourse as long they did not form attachments.
Jedi had especially high midi-chlorian counts, and of them Anakin Skywalker was said to have the highest ever recorded at over 20,000, even higher than the powerful Jedi Master Yoda. Though Skywalker later lost a good deal of his organic body, his cells continued to teem with midi-chlorians.
Although the Jedi Lord Valenthyne Farfalla was known to enjoy fine wine circa 1000 BBY, alcohol was not recommended for Jedi by the time of the Clone Wars. The Jedi Council did frown upon Padawans getting intoxicated, although this was a guideline rather than an actual interdiction.
The shoulder armor itself weighed 12.2 kg overall, was resistant to both blasters and energy blades, and was capable of withstanding hits from both weapon types with only minor surface pitting.
Grandmaster Yoda himself was capable of summoning force lightning in the form of Emerald Lightning. Galen Marek was an extremely skilled user of this Force power, even after his conversion to the light side, rivaling Darth Sidious.
He hasn't learned how to use the ability yet, due to his still-shaky alignment in the Force. One must give themselves fully to the Dark in order to use lightning, and he just hasn't done that. Why was Kylo Ren hitting himself during the lightsaber battle in Star Wars: The Force Awakens?