Above VARIANCE 4, a full-width centered hero — centered headline, centered subtext, centered single CTA, everything stacked mid-column — is the single most common AI layout default. Centered is a choice you make for a reason (a focused auth screen, a genuine single-action moment), not the thing you land on because nothing pushed you off it.
Headline, subtext, and the one button all land in the same mid-column stack — no reason for it beyond it being the default.
Left-aligned copy claims its own column instead of fighting for the page's center line; the CTA sits where the reading flow already ends.