Most of the time it is still the resources.

If you gold out your jewellery you can use Infused on stamina characters but you might have resource issues on most classes.

They’re all close enough that absolute best depends on your build and the content you’re doing. This is especially true for Magicka DPS. For example, Magblades get a good Max Magicka multiplier, so Arcane is often still the best choice. Magplars have a good Spell Damage multiplier solo, so they would lean toward Infused with Spell Damage enchants. Sorcs could go either way, depending if they’re using Bound Aegis and Inner Light (lean toward Arcane) or have a lot of Sorc skills slotted and Minor Sorcery provided (lean toward Infused).

Bloodthirsty is often the best choice, especially in fights like vAS, where the last 25% adds extra mechanics. However, other fights like Rakkhat it’s more advantageous to push damage up front and execute is less of a concern, so Bloodthirsty would be pointless.

For stamina, I don’t think Robust is very competitive. It is mostly a choice between Infused or Bloodthirsty. For solo content, Bloodthirsty is usually better for builds without an execute skill. The last 25% of most targets will go by so quickly on something like stamblade that you often won’t get much use from Bloodthirsty. Also consider that if one skill will kill a target at 25%, then Bloodthirsty adds literally nothing (bad choice for easier content). Infused with Weapon damage glyphs is always good on stamina because they get a high weapon damage multiplier from medium armor and fighters guild skills.

Some math if you're interested. Doesn't include bloodthirsty but still great:
https://tabatta.eu/summerset-infused-arcane-robust/

To add to everyone's response, I find MagDK at most should use one Bloodthirsty. The rest Arcane. More than one BT and I find my Max Magicka is too low.