I think another reason is that biological systems are _fantastically_ complicated - for example, we're finding that the spatial distribution of molecules within

I think another reason is that biological systems are _fantastically_ complicated - for example, we're finding that the spatial distribution of molecules within the cell affect enzymatic processes in ways that may have implications for alzheimer's and dementia. For another, there's various bacterial communities where, if you want to trace the enzymatic pathway for a particular product, you're jumping between species in the community, and not just once - that particular product is the result of multiple distinct enzymatic pathways in multiple different organisms (and whatever else exists in the environment outside the cell). I've been a software engineer for 20 years now, I don't underestimate the complexity of computer systems or software - I think the number of people in the world who could really accurately describe every part of every system involved in showing you this note to you is maybe ten - but we've got nothing on biological systems.