Disable WordPress 6.5 Font Library

add_filter( 'block_editor_settings_all', function( $editor_settings ) {

	$editor_settings['fontLibraryEnabled'] = false;

   	return $editor_settings; 

} );

// Disable the REST API for the font library.

add_filter( 'register_post_type_args', function( $arg, $post_type ) {

	if ( 'wp_font_family' === $post_type || 'wp_font_face' === $post_type ) {

		$arg['show_in_rest'] = false;

	}

	return $arg;

}, 10, 2 );

add_filter( 'rest_endpoints', function( $endpoints ) {

	foreach ( $endpoints as $route => $endpoint ){

		if ( str_starts_with( $route, '/wp/v2/font-collections' ) ) {

			unset( $endpoints[ $route ] );

		}

	}

	return $endpoints;

} );