I'm a big JetBrains fan, but this distinction is just silly. If you look at the way that JetBrains IDEs are packaged, the differences between IDEs all come down to extensions—which are enabled by default, which are available to install at all. IntelliJ Ultimate can be made to have all the features of PyCharm with the right extension combo. And occasionally they break out a new IDE by taking an extension and making it no longer available for installation elsewhere (like RustRover). The entire architecture is one of plugins.

"Integrated" isn't meant to contrast with a plugin-based system (otherwise JetBrains wouldn't count!), it's meant to contrast with a dev environment built out of a bunch of individual tools and terminal commands run separately.