The braces become "invisible" after some training.
Different elements of the program are distingishable.
"+" is different from "if", which is different from "42".
It's all about people, so there are likely not cut and dried answers, but I know I have always found C style code a bit easier to read than Lisp style code. Part of this may be due to other conventions, such as larger indents in C code.
Like you say, with training, the differences are probably not that big a deal, but I don't think they are something to completely ignore, either.
the point is to free yourself to focus on semantics rather than endlessly learning syntax
If you treat the language as a user interface to your computer, shouldn't things that do different things have different appearances, to help you distinguish them at a glance?