Anakin Skywalker is by far my favorite Star Wars Character. I think Haden Christensen did a fantastic job playing him, except for like a few incredibly cringe scenes in Attack of the Clones that we don’t talk about (even though it’s more the writers’ fault than his because they made Anakin super winey and childish).
I want to quickly mention that I have not finished The Clone Wars, so I will not be using anything from that show in my analysis. Basically, I’ll almost exclusively be using the Prequels for my examples.
Alright, let’s get right into why Anakin’s life was a genuine tragedy from beginning to end.

Anakin was born into slavery. Until the day he left Tatooine with Qui-Gon, Obi-Wan, and Padme, he had spent his entire life as Watto’s slave.

During his career as a Jedi, Anakin was completely and utterly failed by the Jedi Order, specifically the Council. And by failing Anakin, they essentially failed the entire galaxy. The Council was far too rigid, and are largely to blame for the creation of one of the strongest and most ruthless Sith to ever exist. Even in Attack of the Clones, Yoda sensed pain, rage, and sadness from Anakin as he massacred a camp full of Tuskans. Yet he still chose to do nothing. Obi-Wan was also to blame. He had been training Anakin since he was a child. He understood the feelings and confusion clouding Anakin’s judgement very clearly and chose to do nothing as well.
If Qui-Gon Jinn were alive, I believe things would have gone very differently. He did not follow the rules as strictly as the other high ranking Jedi. That is the sole reason why he was not in the Council. I’m sure he would have given Anakin great guidance and worked with the Council to find a way to help Anakin from following the dark path he eventually found himself going down, with no return in sight.

As stated by Palpatine before his fight with Yoda, Anakin was to become more powerful than the both of them. He likely had the potential to be the most powerful force user to ever live. However, after losing literally all of his limbs on Mustafar he loses most of his potential and obviously his mobility as well. While he was still incredibly strong with The Force, his growth was significant stunted. Not only that, but his prowess with a lightsaber was a large part of what made Anakin so formidable. He lost an incredible amount of mobility by having his limbs replaced with cybernetics. Not only that, but Anakin’s need to become more powerful seemed to subside once he become Vader. For reasons unbeknownst to me, he was content with being Palpatine’s pawn.

Anakin’s circle was very small as he did not have very many close friends or family. His fear of being alone is what drove him to the dark side. Anakin had already lost his mother, and was deeply afraid of losing his wife as well. However, in the process of trying to save Padme, he killed her as she “died from a broken heart” (it’s also possible that Palpatine could have done it). Anakin doomed the galaxy and lost his only close friends and acquaintances as well. After this, he turned off his heart and emotions and became a cold killing machine.
Vader is but a shell of his former self, fully engulfed by regret and stuck on a path he can never go back on. At the end of Order 66, all that is left of Anakin is his pain, sorrow, and anger. Nothing more, nothing less. This drastic change led to Anakin seeing himself as only Vader, casting aside his past entirely.

Even though Vader was suffering and most likely regretted his actions, he continued terrorizing the galaxy as a Sith Lord as Palpatine’s number two. This is because he consciously suppressed the good in him, essentially “killing Anakin Skywalker” as he put it, and embraced his anger and darkness. He continued to work as Palpatine’s pawn, knowing full well he was being used.
While his life was a sad one, at least we can take some solace in knowing that he died smiling at his son with pride after they “defeat” Palpatine (goddamn you J.J. Abrams).