Say what you will about its merits, but PHP is used by over 75% of websites today[1]. Rumors of its demise are monumentally exaggerated.

[1] https://w3techs.com/technologies/details/pl-php

Only threat to Java is the success of the JVM, that Java could be replaced by another JVM language seamlessly, but the JVM itself will definitely be here and developed 50 years from now.