public function remove_wp_block_classes_and_clean( string $content ): string {
		$dom = new DOMDocument();
		libxml_use_internal_errors( true );
		$dom->loadHTML( mb_convert_encoding( '<div id="root">' . $content . '</div>', 'HTML-ENTITIES', 'UTF-8' ), LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD );
		libxml_clear_errors();
		libxml_use_internal_errors( false );

		$xpath = new DOMXPath( $dom );

		// Query all div elements with a class containing 'wp-block-' or empty divs not containing <br> or significant whitespace.
		$nodes = $xpath->query( '//div[contains(concat(" ", normalize-space(@class), " "), " wp-block-") or (not(node()) or normalize-space(.) = "" and not(.//br))]' );

		foreach ( $nodes as $node ) {
			// Create a document fragment to hold the inner HTML for non-empty elements.
			$fragment = $dom->createDocumentFragment();
			while ( $node->childNodes->length > 0 ) {
				$fragment->appendChild( $node->childNodes->item( 0 ) );
			}

			// Check if the node should be removed entirely or just have its contents moved up.
			if ( $node->hasAttributes() || $node->childNodes->length > 0 ) {
				$node->parentNode->replaceChild( $fragment, $node );
			} else {
				// For truly empty nodes that shouldn't be preserved, remove them without replacement.
				$node->parentNode->removeChild( $node );
			}
		}

		// Extract the content from the temporary root div, preserving <br> tags and whitespace.
		$root     = $dom->getElementById( 'root' );
		$new_html = '';
		foreach ( $root->childNodes as $child ) {
			$new_html .= $dom->saveHTML( $child );
		}

		return trim( $new_html );
	}