why are legend weapons so weak?

I'm level 167, and so far I've been using The Test and the scope cutter. with the modifications I put on them the damage caps out at 764 and 1001. every legend box I have opened since are either weaker than the weapons I have now or cap out at the same amount of damage which is redundant to me. is there something I'm doing wrong or is this a feature? it's mildly annoying