This is simply because it’s much easier to get Sacrificial refinements since it’s a standard weapon. You can get it from every gacha banner. While Evenstar is a limited weapon, so you can only get it from the weapon banner. Plus Evenstar only becomes better than Sacrificial with refinements. So the better weapon is generally the one with higher refinements. Below is a quick table to compare these weapons. They have the following stats and passives at Level 90 Refinement Rank 1: And here’s a more detailed comparison between the two weapons for every notable unit.
For Sucrose
The better weapon depends on Sucrose’s role on the team – but they’re very interchangeable. Here’s a deeper comparison between the two. Still, it’s generally recommended to go with Sacrificial Fragments – especially if it has more refinements.
For Nahida
Sacrificial and Evenstar are both really good weapons on Nahida. Wandering Evenstar best excels with teammates that benefit from ATK. At Refinement Rank 5, it also becomes her best 4-star weapon as a support. However, Evenstar is only better than Sacrificial at Refinement Ranks 3-5. This is because Sacrificial is a great general weapon for additional EM and personal damage. But the additional skill cast doesn’t generate extra particles since she doesn’t generate particles upon cast.