No, they’re pretty much best as a sport or sideshow entertainment. Also drinking games, because nothing says fun like someone who’s pickled chunks of their brain handling sharp objects.
Throwing knives teach you how to throw knives, and nothing else. It doesn’t really translate into other weapons at all. The movement and fundamentals of aiming won’t help you with throwing an axe or a spear, and it won’t really help you to learn, or to adjust your aim.
There’s that rare exception that your character could take someone else’s knife and throw that to kill a third person quickly and quietly. But that’s incredibly situational.
I mean, yes, if your badass knows knife throwing, and you set that up with them doing it in a bar in the first chapter, and 300 pages later after everyone’s forgotten, they sneak up behind someone, shank a guard in the neck, take the guard’s knife and flick it into another guard fifteen feet away before he can hit an alarm… sure, that’s fine. Goofy, situational, over the top, but, you know, fine. But, it’s just not practical as a primary combat technique.