Disable RSS without wp_die or addactions?

I want to disable RSS on my website completely in my theme functions.php file but every recommendation I find says to use wp_die(), which is not correct, according to what I read online. Also, .htaccess is not a theme file so that will not work. Also, add_action uses too many unnecessary server resources.

Anyone have a solution? Technically .htaccess is the correct way but then I could not redistribute my theme, as the / folder usually has its own .htaccess set of rules.

Any help?