Present-day technologies are limited in various ways. Large atomically precise structures exist, in the form of crystals. Complex 3D structures exist in the form of polymers such as DNA and proteins. It is also possible to build very small atomically precise structures using scanning probe microscopy to manipulate individual atoms or small groups of atoms. But it is not yet possible to combine components in a systematic way to build larger, more complex systems.
Principles of physics and examples from nature both suggest that it will be possible to extend atomically precise fabrication to more complex products of larger size, involving a wider range of materials. An example of progress in this direction would be Christian Schafmeister's work on bis-peptides.