Why would this IF statement not work? [closed]

You need to use the AND (&&) operator to make this work. As your condition stands, it will return true no matter which page you are on. The OR operator only needs one true to execute where as the AND operator needs all conditions to be true to execute

I just have one other concern here as you are loading your footer conditionally, and that is, you should make sure that you remove wp_footer() from that condition, you should not load it conditionally as this will break many scripts that is loaded in the footer. So make sure that you don’t load wp_footer() conditionally