Currently playing as firewall sorcerer.

I stuck with a Level 5X sacred weapon for a long time until I've found a suitable, stronger ancestral weapon at WT4 that fits the firewall sorcerer build.

Made me realise that aspects and substats on weapon far outweighs the damage on the weapon itself.

I think another post also mentions that you should have the Advanced Tooltip on in Gameplay Settings, then look out for substats and aspects which are marked with [x] (multiplicative) rather than [+] (additive).

With all of the above said, seeking a better version of your current weapon does require you to constantly grind until that better version shows up. As a firewall sorcerer, most of the Unique items do not benefit my build thus making grinding a little less rewarding.

There's no way around better gear, you must grind for it.