For this case I've made use of fgetcsv()

    // Count Lines
    $handle     = fopen($csvfile, "r");
    $numrows    = 0;

    while (($data = fgetcsv($handle, 0)) !== FALSE) {
        $numrows++;
    }
    fclose($handle);

The second arg of fgetcsv (length) can be null since PHP 8.0