You are correct. The only serious frameworks nowadays are Qt or Electron if you're targeting the cross-platform desktop. There's also wxwidgets, although its python 3 bindings are still being built.

Personally, I'm keeping my eye open on libui (https://github.com/andlabs/libui/) as it is already possible to do some basic things with it. However, it is pretty much in alpha state and I'm slowly writing the Python bindings for it at https://github.com/joaoventura/pylibui/. The thing that I like in the libui is that it is a thin wrapper around platform specific frameworks. Therefore, the library is very small (some 340 KB) and it's as native as the underlying platform calls are..

Regarding Electron, I am writing an application on it, but it is too god damn heavy in terms of memory, disk space and boot time, and web front-end development is absolute chaos these days. Although I'm currently writing my app on it, it is mostly an MVP as I want to make pylibui/libui usable enough to switch to a pure desktop cross-platform library asap..