Node.js takes advantage of this behavior. If you connect to a database in Node.js, you can do other things until you get a response. If you connect to a database in PHP, processing stops until the database responds.
If used properly, this can provide a significant performance boost to Node.js over PHP. Of course, PHP does technically support threading if you use the pthreads library… and Node.js does technically support threading if you use a variety of plugins or extensions. However, in the normal use-case (without add-ons) Node.js can run faster than PHP.
To a lesser extent, this can also be due to the way that a Node.js server runs versus the way that a PHP server runs. A PHP server will generally wipe state between requests because each request starts fresh—launched from NGINX, Apache, PHP-FPM, etc. Node.js, on the other hand, runs non-stop as its own standalone process. This means that Node.js doesn’t have to negotiate database connections between every request, and that will give Node.js a slight speed boost over PHP as well.
There are tools that you can use in PHP to mitigate this problem, too, but they are external tools you have to hook into your process. This is an out-of-the-box feature for Node.js.
When you combine these things, you have a recipe for Node.js being (potentially) faster than PHP.