What is the most complex molecule we can manufacture without the help of proteins? (soft queston) What is the most complex molecule we can manufacture without the help of proteins?

This isn't motivated by anything but curiosity about the state of chemical engineering. I realize “complexity” is a loaded term, so I'll defer to the judgment of the respondent: number of molecules, complex arrangement of bonds, or whatever other measure might be appropriate.
I guess in the field of inorganic chemistry polyoxometalates (POMs) are comparable with proteins in terms of structural complexity. Macroanionic POMs such as Keplerates $\ce{\{Mo132\}}$ 



are also capable of further self-assembly in diluted solutions, producing so-called "blackberries" [1] of a size of around $\pu{0.05 .. 0.1 \mu m}$:



Also, see the post Measure the complexity of a molecule and the corresponding paper [2] of Prof. Lee Cronin, one of the most productive polyoxometalate chemist of current era.


Kistler, M. L.; Bhatt, A.; Liu, G.; Casa, D.; Liu, T. J. Am. Chem. Soc. 2007, 129 (20), 6453–6460. DOI 10.1021/ja0685809.
Marshall, S. M.; Murray, A. R. G.; Cronin, L. arXiv:1705.03460 [q-bio.OT] 2017.