"There are a hundred examples that are specific to whatever app this guy built for the Healthcare company, not all of which are covered by the PHP standard library."

You would need to implement whatever custom code required or use a libruary. You would need to do the same with a framework. No framework offers business health care functionality. Do you think laravel has an ocr skin cancer detector package?

PHP is fast to write. Hearing people from the outside saying its impossible to write a php site that quickly makes me laugh. PHP makes development easy.