Worf's main function was to show how tough a new character was by getting beaten up by them.
Unless it was a Klingon story, in which case he would somehow be stronger with their weapons even though he wasn't raised with Klingons and his combat training would have been mainly federation combat (though I suppose it would make sense for him to surpass them with his access to one of several holodecks on the Enterprise).
Another exception was if it was a child, in which case he was the scary adult laying down the law. But I believe there's an exception to even this exception, though that child did have powers closer to Q's than to humans'. And I can't remember for sure if she did pwn Worf in that episode.
It makes some sense that Worf would be an expert in Klingon combat, because he's such a tryhard that strives to be more Klingon than Klingons since he feels like he has something to prove.
Worf got exposed to Klingon culture and ideals with no context for how they're constantly falling short. He's trying to live up to impossible standards, without knowing that's not really what it's all about. And honestly, he's not doing bad. Except for Alexander. Worf is a horrible father, and given his adoptive parents he really has no excuse.
I love that Worfs horrible parenting has become such a joke because he really was a terrible father. I love Worf, Michael Dorn is fantastic, but the writers had absolutely no idea what to do with Alexander. It all always felt so forced, which I guess was kind of the point.