Why is the Psionic Artificer considered to be better than all other tier 1 classes?

Question

The tier list over on GitP considers the Psionic Artificer to be "tier 0" and lists a few reasons explaining why. The primary justifications given for this (as seen here and here, and debated here) appear to be as follows:

1. Due to a rule on page 232 of the Magic Item Compendium, Psionic Artificers can make pretty much anything that a regular Artificer can.
2. The Spell-to-power Erudite puts all arcane and (with a little bit of tinkering) divine magic in the reach of Psionic Artificers. In line with the normal Artificer and Spell-to-power Erudite tricks, this also allows for exploits like access to a level 1 Haste spell/power.
3. Dorjes can contain higher level powers than wands.
4. Access to Psionics allows for some tricks that can not be obtained elsewhere, such as playing as a sandwich.

This is all well and good and certainly does a great deal to explain why the Psionic Artificer is superior to its non-Psionic equivalent. However, I do not see how this is sufficient to bump the class up a tier or explain why it is superior to the other tier 1 classes. For example, the Spell-to-power Erudite also has access to basically any psionic power and arcane or divine spell and therefore ought to be just as powerful and versatile as the Psionic Artificer. Furthermore, I'm of the belief that actual magic is almost always better than magic items. Is there some factor that I've overlooked?

Answer 1

Tier 0 isn’t really a thing—JaronK’s tier list enjoys a lot of consensus, but only includes tiers 1 through 6. That list mentions the truenamer as being basically broken and not really fitting into the tiers, which is sometimes referred to as tier 7 (or simply “truenamer tier”), but beyond that there are just the six.

Furthermore, for the most part, the tiers very much want to treat classes by their full range of potential—from the naïve no-op build to a full to-the-hilt optimized build. The idea is that for a given amount of optimization, higher-tier classes are more versatile and/or powerful, and lower-tier classes are less versatile and/or powerful. The main point here is that generally speaking, class variants and options aren’t considered separately in the tier list—they just represent more or less optimization. There are a few exceptions—dungeoncrasher, for example—but for classes that are already tier 1, an option that makes them more powerful isn’t really considered relevant.

That hasn’t stopped people talking about the idea of things that are even stronger than what we think of as tier 1. Psionic artificer is notable for having dramatically more versatility than a regular artificer—which is already an incredibly versatile class, even by the standards of tier-1 classes. That’s notable. Sometimes the psionic artificer is therefore called as tier 0, or as the link offer suggests, “If there is a Tier Zero, Psi Arty deserves it.”

Spell-to-power erudite is also a frequent candidate for tier-0 status. Again, we’re talking about a character that has dramatically more spell access than a cleric or wizard, plus most of the power access of a psion. This thread has several people calling it tier 0, for example.

But ultimately, none of these things have even remotely the consensus that the main tier list has. Tier 0 isn’t really a codified thing, it’s just an occasional topic of conversation. Psionic artificer and spell-to-power erudite are some of the most common choices for those conversations. I don’t think you’ll find many people who will say “no, that isn’t tier 0!” though.