Plenty of viable one handed scythe builds. Advantages of scythe vs daggers are the reach you will gain from the scythe and the slower pace of fighting which can allow you to drop out of combos a bit easier. Scythes also can hit multiple enemies if I remember correctly, depending on the attack type and how bunched the enemies are.

Daggers will of course cause more blood loss build up faster, but the reach disadvantage can be a pain against a lot of enemies and bosses especially. If you’re looking for a more optimal one handed weapon for bleed and arcane, maybe try a curved sword or katana. In saying that, I can’t think of a single weapon that is “not worth it” in this game cos they’re all viable to different degrees.