Your system asks for reduced motion, so VFX-JS draws nothing. Demos on this site show plain HTML.
Type
HalftoneInkPresetName
effects/src/halftone.ts:22 ↗import type { HalftoneInkPresetName } from "@vfx-js/effects";type HalftoneInkPresetName = "pure" | "newsprint" | "fogra51" | "swop"