D'art's special weapon in the future just makes Sniper Shot stronger, so you'd basically still be only using her for Sniper Shot. Lol.
If your main teams are either Wind or Water, you can hold off on D'art. Cybele provides a similar but weaker debuff and Belphegor does the same for water. Their debuffs are not as strong as Sniper Shot but it can be good enough if your weapon/eidolon grids are leveled and gives your soul other options than just always having Sniper Shot.