They don’t bring back enough original characters into the main storyline. Johnnys friends are the main ones they don’t bring back because they should be added to Kreese’s story. It makes no sense for them to just add Johnny to Kreese’s story.
They don’t bring Ali back to the main focus, even though she was one of the main characters in The Karate Kid.
They redeemed Mike Barnes, which is messed up because he should have been left off as a villain as he seemed irredeemable in KK3. Plus they’ve already redeemed enough original villains and some of the kids need to be left off as villains.
Instead of using CGI of the original actors when they were young whenever they show young Kreese and Silver they just use completely different actors, which is messed up because Barrett Carnahan looks nothing like Kreese did in his 30s. He should’ve just played Kreese as a teenager.
Mr. Miyagi’s birth date being born in 1925 doesn’t make sense and he should’ve been born in 1916, as he would not have been allowed to immigrate to the U.S. until after World War II. Plus he looked older than 59 in Karate Kid.
Daniel and Kreese never once ask Johnny about his old gang from high school, which is messed up especially on Kreese’s part as Cobra Kai makes it seem like Kreese never knew Johnnys friends. I’m sure Kreese would’ve mentioned Bobby Brown as he was his second best student.
Cobra Kai makes it seem like Kreese always cared about Johnny even though there was no indication about that in Karate Kid.
Kreese and Silver apparently weren’t friends anymore after Karate Kid III as they didn’t get along that well in Season 4. I thought they were forever friends.