Python has an "invisible close brace" character, the newline, which closes a varying number of braces. When you think of it like that, it makes much less sense.
The idea that the end of a block is invisible isn't really right, though. The newline doesn't end the block. The block ends at the next line containing non-whitespace text at a lower indentation level. In other words, it only ends when it becomes visible that it has ended.
In an Algol brace-blocked language (or Pascal, Verilog etc which use begin/end), you can just put stuff in the middle of a block, check that what you've just inserted is balanced, let the editor reformat it, and you're fine. Whereas if you've lost the indentation from
if a:
print b
a = a + 1
So maybe what C's missing is a standardized, popular, universal, automatic fmt-on-save. This eliminates its' issue problem with improperly indented code.