Disable Thumbnail Image Sizes

add_filter( 'intermediate_image_sizes_advanced', function( $sizes ) {

	// Disable specific thumbnail sizes, uncomment the ones you want to disable.

	// unset( $sizes['thumbnail'] ); // 150px x 150px

	// unset( $sizes['medium'] ); // 300px x 300px

	// unset( $sizes['medium_large'] ); // 768px x 0px

	// unset( $sizes['large'] ); // 1024px x 1024px

	// unset( $sizes['1536x1536'] ); // 1536px x 1536px

	// unset( $sizes['2048x2048'] ); // 2048px x 2048px

	return $sizes;

} );