Modern node names are more marketing labels than a description of any real feature size of the underlying process. We can "have" 500pm anytime we want by simply naming a node appropriately. There aren't any serious roadmaps out to the picoscale, but people have proposed a future Angstrom roadmap beyond 1.4nm. 500pm would be A5, or sometime in the late 2030s.

As an aside, 500pm is just about enough to fit 2 whole silicon atoms, so it's hard to imagine it ever being a real description of a feature size.