WCI to Egghead is 2 arcs difference. 2 arcs won't make Luffy magically much faster 2 arcs prior. Alabasta Luffy was a bit stronger than Whiskey Peak Luffy. Sabaody Luffy was a bit stronger than Enies Lobby Luffy. The biggest power up Luffy got was ap thanks to advCoA and advCoA.
No Kizaru cannot dodge Snakeman he could only block it. Dodging is much more efficient. That's why in the first image that you posted Katakuri could kick Luffy's face because he was moving toward Luffy while dodging Snakeman. That's why in the second image you posted he landed Buzz Cut Mochi because he dodged Snakeman punch then countered it with Buzz Cut Mochi.
Snakeman is a ranged attack. Blocking only makes you as a sitting duck you cannot counter attack Snakeman who hits you from a far distance. Moving toward Snakeman while dodging like
Katakuri did is the only way. Plus Snakeman did not use King Cobra its fastest attack that Katakuri could still match in term of speed. Katakuri is faster than Kizaru. He blitzes him.