I think you're massively overstating your case when you say "optimal." There is no evidence anything CL provides is optimal according to any rigorous metric. I could very easily claim Scheme is "more optimal" since it's a much more minimal implementation with the same capabilities. Also I think you are mistaken to equate fewer symbols with easier to reason about symbols, e.g. I find it much easier to reason about complex programs when they are written in a strong static type system, which CL lacks. The type system lets me leverage the computer to help me reason about the program, by type checking.
Then the computer is doing the reasoning, not (just) you. Static typing will certainly help you reason about a larger system, I do not dispute that. I am talking about increasing the capability of the largest symbol system you operate on in your mind without relying on the computer. If the meaning-density of the symbols is higher, your effective intelligence goes up.
