Unset Default WordPress Image Sizes

unset_default_image_sizes.php

add_filter( 'intermediate_image_sizes_advanced', 'ni_remove_default_image_sizes' );
// Source quadlayers.com/remove-wordpress-default-image-sizes/
function ni_remove_default_image_sizes( $sizes ) {
	unset($sizes['thumbnail']);    // disable thumbnail size
	unset($sizes['medium']);       // disable medium size
	unset($sizes['large']);        // disable large size
	unset($sizes['medium_large']); // disable medium-large size
	unset($sizes['1536x1536']);    // disable 2x medium-large size
	unset($sizes['2048x2048']);    // disable 2x large size
 return $sizes;
}