I use PHP as the backbone for almost all my projects, and it's a common misconception that PHP isn't capable of handling large sites. Let me just shoot that down by name dropping Facebook here.
Since PHP 7, and especially 7.2, it has been possible to work with type strong methods which makes it even more suitable for enterprises. (Parameters and Return types).
It does require a bit of self control in order not to be a weak architecture, WordPress is a good example here on how NOT to structure your code. Laravel and Symfony are on the other hand very good examples on how it's done beautifully.
It is also important to remember that PHP is more focused than other languages are. So you can of course you only build backend stuff, while you still need JavaScript to power the frontend rendering.
Jan Vladimir Mostert
Idea Incubator