Yeah, the main difference is this builds wxPython and everything within Python and uses a virtual environment to avoid changing the system site packages. I don’t recommend regular people do things like pip -U (even with --user) because someone might be using some app that is depending on some other version and it’s much cleaner to just segregate everything unless there’s a specific technical reason one can’t.
I misread a post here: Installing Pyfa on Ubuntu 19.10 about missing packages in 19.10 and assumed python-wxgtk4.0 and python3-wxgtk-webview4.0 wasn’t available in the standard apt repos and wanted to post how I did it without having to modify the system as much as possible.
In any case, being able to build wxPython oneself could be useful if some other distro doesn’t have the wxgtk modules already available.