Ok, so this is a slightly different take to all the "apps" out there that are just fancy wrappers of some browser widget. It makes it incredibly easy to get started.
Or does it? Instead of the usual paradigms of desktop applications you now have to handle all the different ways that webapps are more complicated than desktop apps. Say, you need to have global state and need to track user interaction through page loads... Yes, JavaScript apps might make all that easier, but now I need to understand Python/Flask+HTML/CSS+JS and a little bit of Qt. With that level, I can just learn PyQt and things will be a lot faster and less of a headache to debug and maintain.
Don't get me wrong, I like the idea of making desktop application development easier. I just don't think introducing more moving parts is going to achieve that.
Depending on your skills and requirements, designing an UI with web tools can be easier then with pure Qt.
The presented software could be understood as a lightweight alternative to Electron where the Hackernews community just collected good argumenst for and against at https://news.ycombinator.com/item?id=16435688
I personally like all the ingredients (Qt, python, the web). The only thing which could steal the show is the quality of the browser engine integrated into Qt. Since typically Qt is some shared library (especially when used with Python), the whole software will be not as monolithic and probably "pixel perfect" as an Electron application is. On the other hand, this is what you are used from regular web.
Or does it? Instead of the usual paradigms of desktop applications you now have to handle all the different ways that webapps are more complicated than desktop apps. Say, you need to have global state and need to track user interaction through page loads... Yes, JavaScript apps might make all that easier, but now I need to understand Python/Flask+HTML/CSS+JS and a little bit of Qt. With that level, I can just learn PyQt and things will be a lot faster and less of a headache to debug and maintain.
Don't get me wrong, I like the idea of making desktop application development easier. I just don't think introducing more moving parts is going to achieve that.