https://doc.qt.io/qt-6.2/qtwebengine-features.html
There is an API and python bindings. Falkon and qutebrowser (possibly others) use it for their browser engine. It uses Chromium code underneath.
Now if just Qt for WebAssembly[1] would support it we could go full circle...
[1]: https://doc.qt.io/qt-6/wasm.html