George Lucas believes Anakin should never have been a Jedi, and Qui-Gon's recklessness in wanting him trained led to his fall to the dark side. Qui-Gon's advice to the Jedi Council about living in the present moment ultimately led to fatal mistakes, with Jedi Master Sifo-Dyas ignored.
Star Wars revealed the real reason Qui-Gon Jinn was so defiant toward the Jedi Council when it came to training Anakin Skywalker. In Star Wars: Episode I – The Phantom Menace, Qui-Gon believed that Anakin was the Chosen One.
Qui-Gon is one of the most powerful Jedi in the saga: highly skilled in the Force and mastering abilities that other Jedi couldn't, including the ability to consciously manifest after death. But more than his abilities as an individual, it was his maverick philosophy that the Emperor feared.
Because Maul punched him with the hilt of his saber and then stabs him faster than Qui-Gon can pull back his blade. So Qui-Gon lost because Maul was physically stronger and quicker than him. Qui-Gon is skilled but not a prodigy. And he's quickly worn down by Maul in both their encounters.
He was not so content to blindly follow the Republic. and was more sensitive to the will of the Force. Qui gon represented the ideal Jedi, and had he been able to sway others within the Order, it could have presented problems for Palpatine.
Star Wars FINALLY Reveals Why Qui-Gon REFUSED to Join the Jedi Council - Star Wars Explained
What did Darth Vader think of Qui-Gon?
Qui-Gon Jinn: the One Jedi of Value
Master Qui-Gon Jinn's words echo in Vader's mind. There's no anger, nor hatred in this memory – Vader simply recalls one of the first lessons the Jedi Master slyly gave to young Anakin Skywalker.
Whether Vader thought of Qui-Gon specifically was not mentioned. However, it was safe to say he most likely did. Vader felt regret over how he disappointed everyone who cared about him, like Obi-Wan, Padmé, Yoda, etc.
Darth Maul was a greater, stronger and younger swordsman than Qui-Gon Jinn, and more powerful. Darth Maul knew that, Darth Sidious knew that, and for that matter, at the time of their first clash on Tatooine, Jinn himself understood that.
The easy explanation was that Qui-Gon didn't use the dark side to sustain himself. He was wounded, and he wouldn't have dreamed of using the dark side to keep himself alive. So, he died of an injury that a dark-sider probably could have survived.
We are led to assume this as in TCW Qui-gon admits his training was incomplete. He could only appear on Mortis, anywhere else he could only be a disembodied voice.
After Qui-Gon was killed by Darth Maul, Yoda was saddened, but continued to disapprove of Qui-Gon's unorthodox ways, regarding them as "defiance". After he failed to defeat the Emperor, Qui-Gon's spirit taught Yoda the Shaman of the Willis.
What would have happened if Qui-Gon Jinn survived?
Dooku, AND Anakin, would be less likely to fall to the dark side if Qui-Gon was left alive and Maul's sympathetic past would never be revealed. For the former, Order 66 wouldn't be executed since Dooku wouldn't be the one planning to do that on the clones.
Qui-Gon Jinn, who is considered a maverick Jedi Master by his colleagues, might have been able to keep Anakin on the path of the Jedi, had he not been killed by Darth Maul. Star Wars' Qui-Gon Jinn would have been the ideal mentor for the young Anakin.
Qui-Gon was Dooku's apprentice. Dooku loved Qui-Gon like a son due to their many similarities; both were individualists, idealists, and both had knowledge of the Force that was unique.
It's already well-established that Qui-Gon was incredibly strong with the Force. He continuously studied the ways of the Force and eventually learned enough about the Cosmic Force and the Living Force to unlock the secrets of eternal life.
You can also see how much Qui Gon Jinn's death affected Dooku when he was talking to Obi Wan in AOTC. Look at the raw, pure emotion Dooku feels over a decade after Qui-Gon died. It affected him significantly.
Obi-Wan is good at letting his emotions go. He feels them in the moment, the anger and sadness over deaths of ones he loved like Qui-Gon and Satine. The guilt and pain over Anakin's turn. He feels them deeply, and then lets them go.
Through burning the Jedi after death, the possibility of the Force living on as an echo through the dead body is removed, meaning the Jedi in question are fully at peace.
Ren was good but Rey was able to beat him every time they fought. However, he wasn't even fully trained and even he would have had a massive problem fighting Maul. Even in his older age, Maul was still way more skilled than anyone Rey faced and that would be the end for her. Maul would just be too much for Rey.
By the time of Episode 3; Anakin is in his prime, and already one of the Jedi Order's most powerful “masters” (although technically still a knight), just behind Obi-Wan, Windu, and Yoda. Maul wouldn't stand a chance.
The Council, however, felt Anakin's future seemed clouded and uncertain, and deemed the boy too old to begin training and dangerously full of fear and anger. They refused to allow Qui-Gon to train Anakin, but the Jedi Master nevertheless kept the boy as his ward as he returned to Naboo.
Qui-Gon Jinn discovered Anakin Skywalker, the prophesied Chosen One, during the fall of the Galactic Republic. Forty-one years before the Battle of Yavin, Shmi Skywalker gave birth to a son named Anakin Skywalker. Though she could not explain it, there was no father involved in her child's conception.
