The downside is that if by pasting or typing you end up with too few or too many }s, the entire rest of the file gets messed up, nesting everything under the cu

The downside is that if by pasting or typing you end up with too few or too many }s, the entire rest of the file gets messed up, nesting everything under the current function or ending a class early - in the eyes of the compiler, making it produce a torrent of meaningless error messages, and of the editor if you hit the reindent shortcut. This happens to me all the time in C, and significant indentation totally avoids it.