How is this different from some language not realising that a statement should be inside of the curly brackets instead of outside?
It's like static type checking: The class of errors the compiler can catch is larger when it's present. Likewise, with visible scoping characters, the class of errors the compiler can catch is larger than when they are invisible.
Yes, but can it determine scope if things are poorly-bracketed? Because that's the fair comparison.
That's not true of indent mistakes. Semantic whitespace is lossy -- there's data contained in those brackets that some people think is low-value that it's expendable for the sake of saving keystrokes, but it does have value in practice.
Flat is better than nested