Vector (or even simple polygons to a degree) already allows both of those things (if interpreted separately, not infinite meanings).

Well, the meaning part would require a bit of work but you could put small detail that would only be visible when zoomed in. Like you could make the edge of that iris have little people and houses and trees (though it’d be a massive pain to do manually for the whole thing, that and it’d be kinda wasteful data-wise)

Unless maybe you mean something more like a fractal when you say zoomable. Though there have been vector drawings that people did like that (though I don’t think it actually repeated endlessly, just ended where it started… and it is still manually designed thus finite in content).