Was he even any good at fencing? His most noteworthy achievement as an adult was decapitating an 80 year old man. Woo? I'm sure there are very few 80 year olds who any of you couldn't box into an early grave. Obiwan handed Anikan his ass. Yeah. What are the odds that there wasn't one Jedi left in the galaxy who could lick a severely crippled Lord Vader in a fair fight after their ranks and the kindergarten had been decimated? What are the odds that there wasn't one hundred Jedi left in the galaxy who could lick a severely crippled Lord Vader in a fair fight after their ranks and the kindergarten had been decimated? On man... 1/4 of a man vs 1000 Jedi who escaped Order 66? I smell something fishy. You can vote as many times as you like in the pole.
Well they started with shooting at him. Maybe Vader only wanted to ask them if he could get the plans back.
When you shoot at some one and your gun doesn't work, you're in a bind. You'd think that star wars would have invented wide beam blasters or fragmentation grenades, or sonic weapons to deal with Jedi after 10 thousand years of picking on the little guy earning minimum wage.
The Geonosians had sonic weapons in Arena fight. And we've seen plenty of termal detonators and other explosives. The closest we've seen to a wide beam blaster is the stun setting blue donut, which the lightsabers can also block.
To give an honest answer to this question, I think being The Chosen One meant Anakin was already supposed to be exceptionally power as a Jedi, and by opening himself up to the Darkside he became even more powerful. And as a Sith he also would have been a lot more brutal and ruthless. And I have to disagree with the assessment Obi-Wan "kicked his ass", they were pretty even matched for the majority of the fight, which took up quite a bit of the end of the movie. Obi-Wan only won because he more or less got in a lucky shot when Anakin tried to jump over him, it's hard to say how the fight would have ended up that hadn't happened.
They dueled a lot. Obiwan knew all of Anakins predictable power moves and how to counter them because they had pretend fought a thousand times.
Technically, he was still Anakin in that moment--an easily manipulated dumbass, but still Anakin. Obi-Wan was a superior duelist to Anakin / Vader. Even as ROTS Vader had fully given himself to the Dark Side, filled with murderous rage toward Obi-Wan, he could not defeat his former master. Kenobi was intelligent, had valuable experiences Vader did not (e.g. defeating a Sith Lord as a Padawan, and other feats across his career), and on a physical level, his natural creativity and understanding of the Force supported each other to the degree that no lurching dumbass like ROTS Vader was going to defeat him. The ROTS duel only lasted as long as it did (in-universe, not Lucas' failed attempt to make the duel a spectacle) because Kenobi did not want to kill Anakin, despite that being his job. Kenobi getting the "high ground" was not luck, but strategy, one he knew dumbassed, arrogant Vader would not respect, hence the expected finale of the duel. Vader (or Anakin) had his talents, an advantage with his connection to the Force (even after loosing limbs), which was enough to be overwhelming to most surviving Jedi...but that would not give him the edge over individuals (e.g., Obi-Wan, ROTJ Luke) who were at incalculable levels above him in the aforementioned blend of creativity and understanding of the Force. Yep. So, to address your first question, there's always someone better.
This thread brought up another question for me. Do we know how many Jedi Vader actually killed himself vs how many were taken out by Inquisitors?
I think it's said he killed the Jedi Librarian (the one who told Obi-Wan in AoTC that a planet not in the Jedi archives was impossible) and there's another death of a Jedi Master in Jedi: Survivor, although similarly they're more of an archivist and probably haven't had much time to keep up their training in lightsaber combat... and they STILL come closer to killing Vader than Obi-Wan. Hell, even Ahsoka doesn't really look like she's losing to him in their Rebels fight - she's just cut off part of his helmet like Kenobi did (but not damaged his life support controls).
Jocasta Nu. And none of them have the personal connection that Obi-Wan has. So, yeah, they're going to be more likely to go all out in their efforts to kill Vader.
And then Kenobi kicked Annie's ass again in Kenobi. Their final rematch was an even contest until Kenobi literally took a dive.