Disagree. The parens are a missed opportunity. If you use geometry instead, you gain extraordinary new powers of analyzing and editing large programs in 2 and 3 dimensions. Not possible with the parens. The benefits still are not obvious but we're working on publishing more data and tools
Well, then have fun programming in Befunge, exactly the programming language that will fullfill your bidimensional desires.
Honestly, there is no flaw in the parentheses. You just need to write more Lisp.
The parentheses are one of the best things in Lisp.