The major benefit with PHP is the low development time. You can write a website in PHP much faster than you could with Node.js. PHP is simply easier to work with than Node.js. Things like GET, POST, and SESSION information is simply a variable that you reference. Doing the same things in node.js is trickier because they require node dependencies – which vary in quality. Next, PHP was built to work nicely with databases like Mongo, and MySQL. In PHP you can make database query without falling into the callback hell that you experience in Node.js. It is not impossible or impractical to work with databases in node.js, I have done it plenty of times. However, synchronization of the database calls can be tricky and requires more code than it does in PHP.
Another key point is that PHP has been out for a longer amount of time so there is an abundance of code on the web for reference. Not only is there more code but there is also an abundance of tutorials, and books written on PHP. The last reason why I love PHP is that it is really easy to deploy. If you updated a file all you have to do is upload it to your apache web server. That’s it. With Node.js you would have to upload the file and restart the server for the change to take effect.
Compared to PHP, Node.js is a newer language. There is currently a lot of people actively developing for it. Therefore, the libraries that you are using are newer and are often faster than their PHP counterparts. NPM is a lifesaver. NPM offers thousands of modules at your fingertips which can easily add functionality to your project.
I don’t want to sound like I hate Node.js, I enjoy using both PHP and Node.js. PHP is better for smaller projects due to it’s fast development time. I would recommend Node.js for any project that deals with heavy database usage. The perfect use case for Node.js would be for a web API. If your project is heavily dependent on HTML - like a blog- I would urge you to use PHP.
If you are still undecided, just learn Node.js. It pains me to say it but, Node.js is slowly taking over PHP.