The main purpose of the relic weapons is to increase longevity of the content. Like the weekly lockouts and daily bonuses they are in-game to keep you playing and paying. Luckily you do not need them! Those few stat points are not going to make much of difference and so aren't really worth it.

It's much easier to have fun in-game if you ignore this bullfrog and who knows you might get it done eventually while doing other tasks without focusing on it itself.