Wow a genuinely unpopular opinion, let me go ahead and rip into it like the good little keyboard warrior I am.
first, ninja can’t be the worst class in the game because, without ogmur (one of the rarest damn items ever ffs), knight is the most boring, mediocre, shit class I’ve ever had to suffer with. Objectively, without my opinion, the worst class is assassin, it offers no meaningful group contribution apart from being able to insta bosses if you cheat hp scaling and lag, it has shit dps on its own, and its a class designed for leeching (I have a lot of fun with sin btw, 9/10 class would recommend).
It is not slow, and it does good damage, especially considering it pierces enemies and can throw a star.
dps graph of highest damaging classes per weapon compared with the ninja. All tops set for each class, and no buff. Warrior is really the only class significantly better than it, and thats to be expected since it has even lower range and doesn’t pierce enemies
It is objectively just a ridiclously fast class and you were totally lying when you said its slower than other classes. Only if you go for a raw speed build on something like a dagger class will they even compete with ninja.
The only thing you have is that it is not very tanky and short ranged, which is somewhat true, and, even though it can be accounted for with ut’s, I’m trying to keep in mind that not every player can get these UT’s.
Even with that in mind though, every class tends to have some sort of draw back to it.
All this means is that the ninja can be considered somewhat of a glass cannon, which makes it terribly fun to play, you can zoom yourself around the realm and shred everything to absolute bits, you just have to be mindful, pay attention, and actually dodge (it’s almost like ninjas were skilled warriors from the past, who were adept at hand to hand combat and didn’t rely on heavy armor to just deal with any attacks thrown at them).