I really have no electrical engineering knowledge, so this question might be naive. Given that we are approaching a hard limit (the size of the atom), I wonder

I really have no electrical engineering knowledge, so this question might be naive. Given that we are approaching a hard limit (the size of the atom), I wonder wether we could branch out into (true) 3d? So far everything is 2D and if I think of the brain I picture it as an interconnected 3d-blob, which just seems much more sensible.