Does it makes sense to have {post}/feed?

Yes, it’s a core feature in WordPress, and /post-name/feed/ is a post-specific comment feed and is one of the built-in feeds in WordPress — see https://wordpress.org/support/article/wordpress-feeds/ which says:

Comments

Your site has feeds for all comments on the site, and each post has
its own comment feed.

Site comment feed:

• http://example.com/comments/feed/ (permalink format)
• http://example.com/?feed=comments-rss2 (default/plain format)

Post-specific comment feed:

• http://example.com/post-name/feed/ (permalink format)
• http://example.com/?p=123&feed=rss2 (default/plain format, where the 123 is the post ID)

You can disable all feeds, if you want to, but people would no longer be able to get updates like recent posts and comments from your site via feeds or feed readers..

But for completeness, here’s an example which works with the post-specific comment feed, where this code sets the HTTP status to 404 when accessing a comment feed:

add_action( 'do_feed_rdf', 'my_disable_feeds', 9 );
add_action( 'do_feed_rss', 'my_disable_feeds', 9 );
add_action( 'do_feed_rss2', 'my_disable_feeds', 9 ); // RSS2 is the default feed format
add_action( 'do_feed_atom', 'my_disable_feeds', 9 );

function my_disable_feeds( $is_comment_feed ) {
    if ( $is_comment_feed && is_singular() ) {
        status_header( 404 );
        exit;
    }
}