I think there are worse things than modern PHP (speaking as somebody whose primary contact with PHP is being traumatized by legacy PHP 7 projects). Afaik, the only places that will start a new PHP application today are places where the expertise is in PHP and Laravel/Symfony. I don't see a big enough benefit from migrating to a whole new stack that wouldn't be accomplished by some focused maintenance and refactoring if you're already working with PHP 8.1.
