IDE's are handy if you do not know how to setup your local testing environment, however, it is not hard to setup that local testing environment, there are sever

IDE's are handy if you do not know how to setup your local testing environment, however, it is not hard to setup that local testing environment, there are several options online to have an installer do all the work of installing a webserver and a dynamic webserver language like PHP. The pro's of that are that you develop directly into a setup that is comparable with the real deal and issues that come floating to the surface will also do in the production environment. Second, a finished product just needs to be copied to the production server to simply work. Third pro is that when you use a development environment you simply do not need an IDE, a relative simple editor with syntax highlighting and snippet management will suffice. The downside of IDE's are that they tend to make the development road overly complex and most have their own quirks so you have a relative steep learning curve for that and it's hard to switch so you are more or less jailed to a particular IDE. All this time on learning your IDE and learning to deal with it's quirks are better spend on your web project.