Changelogs, really useful?

[Andrea Crotti <andrea.crotti.0@gmail.com>]

It's not really a question about emacs maybe (even if we can automate
things) but more general about programming...

I was wondering if it's still so useful to write detailed Changelogs.
I mean all the software is under revision control, and doing small
commits often I write a commit message for only one function, which
would be exactly what I add in the changelog.

I don't like to write things twice, and also history in the control
revision system is much more detailed, does it really make sense to add
changelogs?

I think that only the changes that involve the architecture or how to
use the software should be really important, but the default style on
emacs is quite detailed.

How do you manage?
Write twice? Write only in the changelog/scm? Other?

Thanks