They come with a bunch of "pre-configurations". I used to have PyCharm, and now I've switched to IntelliJ. I can still do everything I could with PyCharm, which was itself a superset of WebStorm.

Sure, some things are organized a bit differently, but basically, if you want to use multiple languages, just get IntelliJ, and you'll be set. It's cheaper than buying several other products, too.

The only one that seems a bit different is CLion, in that it does things that IntelliJ doesn't, and vice-versa.