When Dooku was still with the Jedi Order, he was considered to be one of the greatest (if not the greatest) lightsaber duelists of his generation. Anakin really wasn't as good of a duelist as many people hype him up to be.
In Canon, the only people who are indisputably better duelists than Dooku are Darth Vader, ST Luke Skywalker, SoD Darth Maul, Palpatine, and Yoda. The debatable people include Obi-Wan Kenobi, Kirak Infil'a, Ahsoka Tano, Mace Windu, and Quinlan Vos. So Dooku is far from being the worst duelist.
Count Dooku lost to Anakin because Anakin was a lot better. Through more training, missions in the Clone Wars, and perhaps his midi-chlorian count, he was almost at his peak. People get shocked though because the prequel trilogy and didn't really show his progressions and didn't show how powerful he was.
Anakin is one of the best, if not the best, lightsaber duelist across the 9 movies. Even aside from his connection to the Force, he showed immense skill, ingenuity, and power when engaged in lightsaber duels, such as his fight against Count Dooku.
Dooku was a practitioner of Form II: Makashi. He was regarded by many as one of the greatest duelists of his time, on par with Mace Windu, whom he had bested before in sparring duels, and was considered by many as second only to Grand Master Yoda prior to the Clone Wars.
Another contender for the weakest Sith could be Count Dooku, or has he's also known Darth Tyranus. Dooku was a cunning and talented Sith Lord, known for his swift skills with a lightsaber and his ability to manipulate populations.
Dooku defeated Obi-Wan, but Anakin in turn disarmed him, severing his hands and holding his sabers at the count's neck. To Dooku's shock, his secret master then told Anakin to kill him. Sidious had indeed betrayed Dooku, and a flick of Skywalker's wrists ended the count's life.
In Star Wars Legends and Canon, Galen Marek (Starkiller) is the only Jedi (other than Obi-Wan Kenobi) to put a beat down on Darth Vader/Anakin Skywalker.
Apart from his wife, there's no one Anakin loved more than his own mother, Shmi. Her tragic death in Episode II: Attack of the Clones, was arguably the first step in his turn to the dark side. Anakin wanted to return to Tatooine and free his mother from slavery but once he returned it was too late.
During the early days of the Clone Wars, Skywalker served as a Jedi General in the Grand Army of the Republic, commanding the clone troopers of the elite 501st Legion against the Confederacy of Independent Systems. After receiving his knighthood, Skywalker oversaw the Jedi training of his own apprentice, Ahsoka Tano.
Anakin regrets this decision, and Palpatine reasons with him saying that Dooku was too dangerous.
Anakin and Obi-Wan board Grievous' ship, the Invisible Hand, and confront Dooku, who knocks Obi-Wan unconscious, leaving Anakin to face the Sith Lord alone. Anakin gives in to his hatred of Dooku and uses his anger to overpower him, severing both of Dooku's hands and leaving him helpless.
One of the main reasons why Yoda would've won against Anakin is simply because he was far better trained than him. Yoda could see the moves his opponents were going to make before they made them; therefore, battling against Anakin would've put him at a far heavier advantage.
1 Mace Windu
He was the Jedi Order's best duelist due to his usage of Form VII Vaapad combat. Windu was a rare Jedi able to harness the Dark Side energy of both himself and his foes in combat, using it to the Light Side end of protecting the galaxy. Mace Windu turned the tide of several battles in the Clone Wars.
Dooku could have not beaten Yoda in Geonosis, meaning that the fight would have ended with Dooku either killed or captured had it continued. At that point, the only two Force-sensitive warriors who could beat Yoda in a fight were Mace Windu and Darth Sidious.
Ezra, though not as strong or as experienced as Anakin, nonetheless shared a lot of similarities with the prophesied chosen one. They were both strong with the Force and had very similar temperaments in terms of being reckless, determined, and impatient.
C-3PO (/ˌsiːˈθriːpioʊ/) or See-Threepio is a humanoid robot character in the Star Wars franchise who appears in the original trilogy, the prequel trilogy and the sequel trilogy.
Anakin Skywalker was a living vergence in the Force, and as Darth Vader he was a force to be reckoned with. But was he more powerful than Luke? As powerful as Darth Vader may be in Star Wars, he pales in comparison to his son, Luke Skywalker.
In a Vanity Fair interview from 2005, George Lucas went deeper into why Anakin became much weaker as Vader. In the interview, he explained that because Anakin's limbs were severed and replaced by robotics, it was harder for him to use the Force than it was before his battle with Obi-Wan.
The Chosen One was born during the era of the Galactic Republic; Anakin Skywalker, the son of Shmi Skywalker, was exceptionally strong with the Force, possessing an unprecedented level of more than twenty-thousand midi-chlorians in his blood.
Anakin Skywalker
During that battle, he learned why Qui-Gon supported and defended Anakin, when he showed how strong his connection to the Force is. Dooku had very little respect for the young Jedi Knight, despite his bravery and unbelievably strong connection to the Force.
Bottom line, Dooku never considered himself a Sith. And he wasn't; he was a man looking to change the galaxy in a way the Jedi were unwilling to try. And that is why he joined the Sith and became Darth Sidious' apprentice, Darth Tyrannus. When Dooku became Sidious's apprentice, he was already an elderly man.
If there was a fight between Anakin Skywalker and Mace Windu, Mace WIndu would definitly win. We have to remember that Darth Vader and Anakin Skywalker are two different beings, and Anakin at his prime was right before he cut off Mace WIndu's hand, and that is where Darth Vader originated from that moment.