PHP share-nothing architecture is awesome. It's amazingly simple and it scales to arbitrary size.
At which point there’s little difference from <everything else>.
And in my opinion PHP tends to be ugly and less readable by default.
The mod_php "share-something" question was always more relevant for ops people.
But architecture of PHP applications is simple and it works. I like simple.
There's nothing PHP specific about share-nothing architecture. It's often refereed to as stateless application layer in other camps.