Do we still need to include a “if (have_posts())” in templates?

I include this logic in my template all the time

if ( have_posts() ):
 //show content
else:
 //show content not found
endif;

But recently I began to doubt its necessity, WordPress will turn to 404.php when no post found, it seems no need to add this logic in normal templates, else will never be triggered, is it?

When I look at WP::handle_404(), I think that the 404.php template will not be loaded, even if there are no posts, if:

• We are on the homepage
• It is a search
• It is a taxonomy term that exists, but has no posts attached to it (and it’s not paged)
• It is an author that exists, which has written no posts (yet) (and it’s not paged)

So in these template files, have_posts() can be useful.