That makes sense, there are probably some more complex use-cases, but for those I would personally not use PHP (e.g. if real-time communication is required or linking together many microservices and having to do operations that involve more than a database and file system).
Though for a small-ish site (say <150 users), such techniques are typically not necessary.
The PHP apps that I have created handle millions of monthly users without issues, so I would say that probably specific techniques are needed more to implement a given functionality instead of to achieve a better performance.