How to remove title tag with this filter

This should have worked (the part of the sprintf at least as I don’t have access to the original code.

Try give a higher number:

add_filter( 'generate_featured_image_output' , 'remove_image_title_archive',100);

Another solution will be removing the filter before applying yours,
like this:

remove_filter( 'generate_featured_image_output', 'remove_image_title_archive',10 );

Important: To remove a hook, the $function_to_remove and $priority arguments must match when the hook was added. This goes for both filters and actions. No warning will be given on removal failure.