Article III grants the Supreme Court judicial power, it does not grant the Supreme Court any legislative power at all. It directly affirms what I said.

Nothing I’ve said is even remotely controversial. No Supreme Court justice has ever claimed to have legislative power. It’s honestly quite shocking that people are willing to dispute the most basic concepts in civics.

> Article III grants the Supreme Court judicial power

And, contrary to your description, that power is expressly not a power limiting it only to “determine constitutionality, and interpret existing legislation” whereas trial judges have “huge amounts of discretion in making their judgements” that the Supreme Court lacks (in fact, as the Supreme Court has, but rarely exercises, appellate power over fact decisions as well as law, its domain is broader, in jury trials, than that of the trial judge, who is the original trier of law but not fact.)

Lower courts have original jurisdiction over nearly all legal actions commenced in the United States. You absolutely do expect trial court judges to exercise a much greater level of discretion than appellate judges, regardless of whether it pertains to matters of law or fact.

However, none of that is to distract from the fact that, contrary to your misinterpretation of Article III, judicial powers do not bestow any legislative powers whatsoever.