Vinny was a popular movie in 1992 and he did a good job in it. It seemed that the film should've given his career a boost. But instead, if we look at his filmography, we see that it was really the end of his prime and he did almost nothing of importance between Vinny and Cobra Kai.
Why? What happened? Why did Macchio's career essentially die in 1992?
His career did not end in 1992. He always played a persona based on "Karate Kid". He outgrew it. I have seen him in films made after 2000 and he's good, just not playing that same schmaltzy character.
He has always been a very likeable actor who played likeable, affable young men in his roles. When he hit his 30's and 40's....he still had the look and persona of a likeable, vulnerable young man, but was a veteran actor who probably did not want to be typecast that way.
And at that age, he wasn't going to be a good fit as a leading man, or an action star....which left him in the character actor/supporting roles lane. He does just fine in his choices and performances--he's a professional. But he doesn't have a ton of range....primarily because we all like him best as Daniel, and always view him as such when we see him on screen. Like it or not, he is typecast.
All that said, he has made a great career out of being Daniel, and the Cobra Kai comeback was a brilliant idea. People love nostalgia (when done right). William Zabka, as well, is just brilliant in how he portrays a middle-aged Johnny.
You know, it's interesting, Matthew Broderick is another one who took a long time to really start looking like an adult and to come into his own in his post-teenage years, but he's been WAY more successful than Macchio has been. It's funny, I don't think of Broderick as a SUPER successful actor, but he's certainly very successful in comparison to Macchio and I bet Ralph WISHES that he had a career as successful as Matthew.
Broderick is a great comparison. His revival came via the theater/Broadway…..but yes, he also was at risk of being typecast in the boyish/affable type that you just couldn’t picture in leading man roles.
His career may not have ended in 1992 but I don't think it's an exaggeration to say it went on life support. All you have to do is look at his filmography to see that he hasn't been a great success as an actor since Vinny. For one, he really hasn't been in much. And for another, most of what he's done are one-off TV appearances and occasional roles in small movies that no one has heard of.