And probably never will. There are a bunch of projects but they are not very good or complete.
The problem is that "good" requires massive amounts of work that is beyond the capacity of single person / small team of volunteers i.e. typical open source project.
Which is why Flutter (and Electron) are the only reasonable technologies for desktop apps that I see today (and in the future).
They get majority of investment from other place: 99.99999% investment in Electron is investment in Chrome.
99% investment in Flutter Desktop is investment in Flutter Mobile.
Flutter Desktop and Electron will continue to benefit from massive investments in Chrome and Flutter Mobile. No other project building desktop UI can come anywhere close this level of investment.
Coworker of mine is using Fyne (for Go). So far the one issue that was found was the use of OpenGL, which on certain video cards, on Windows, in a remote-desktop session may not work (it works if you have NVIDIA drivers for example), or if you force `mesa` software rendering on top.
These little details are usually not a concern, until they become a sudden requirement. Another one is Accessibility, which actually helps in other ways - you can automate UI test, or just automate things through it without relying (to a degree) on the kit's framework. In a way it serves to prove that the UI toolkit does diligent job of presenting it's widgets to a Reader.