When I first started writing Python apps using Pyside/Qt4, it was just before the transition to Pyside2/Qt5.
I put off moving my Captain's Log app from one to the other until I couldn't put it off any longer. Then, it seems only a year or less, we have Qt6 now.
I think my timing was more down to the production readiness of Pyside2, which meant I had to hold onto using PySide and hence Qt4 before PySide2 was ready/mature enough to trust porting my existing app to.
When I first started writing Python apps using Pyside/Qt4, it was just before the transition to Pyside2/Qt5.
I put off moving my Captain's Log app from one to the other until I couldn't put it off any longer. Then, it seems only a year or less, we have Qt6 now.