PyQt is free as long as you don't charge for it. It is under a GPL license/commercial license, so if you wish to sell your game or what ever, you need to pay. PySide is not actively developed anymore.
If you want something active, use PyQT. It works on all major operating systems (Yes, even IOS and Android) and NVDA at least works OK with it. If you want an example of a program that uses QT, checkout:
https://en.wikipedia.org/wiki/Category: … at_uses_Qt
QT comes with a whole lot of goodies including a web browser and db support as well as the ability to use censers and blootooth.
It is currently one of the most robust and accessible cross-platform frameworks out there (if not the only one that goes on IOS and Android).
But frankly, if you are creating a game, you don't really want native UI support. You want a blank screen where you can grab user input, use accessible_output and play sounds.
PyQt is really tedious, but it gets you into good coding practice if you use it like the guides say to. Checkout:
http://zetcode.com/gui/pyqt5/
But you only want this after you finish something like Learn Python the Hard Way.