Help me understand the Benefit vs Risk from Witch ascendencies.

Both seem to have a design philosophy of self damage for a benefit, but neither seem to provide a benefit that puts it ahead of other classes for the risk you're taking on to do it.

Blood Mages first node that you're forced into taking requires you to now pay a life cost on every single skill in addition to its mana cost. From what I've heard the life orbs that drop aren't very helpful, so you're basically just adding a tax onto every spell now. The rest of the time you're trying to counteract this downside.

Aren't you sacrificing a significant amount of potential power to try and get this to work compared to other classes? The benefits for the rest of the tree don't necessarily seem *that* helpful.

As for infernalist they might follow the same problem, but to be honest I can't tell because every discussion about Witch seems to be how problematic Blood Mage is. (Which obviously this post is also doing.)

It doesn't seem as bad, but I'm worried to spec into it because one of the early nodes just seems truly awful. Grinning Immolation meaning I'm self damaging every single time I crit. With the only benefit being an extra +30% Crit Damage. Which is something that exists on it's own in the skill tree. I mean it's extra damage all the same, but it just seems bad compared to other classes.

I'm very early on in this game, so I'm trying to figure out whether I'm just misunderstanding something, or Witch is just worse than other classes, which is sad because I really like the mechanic of sacrificing something for power.