You can have a Web UI in desktop app. Just run the app with embedded kestrel web server and make all UI in HTML. And it will look pretty good an all platforms.
That's Electron, .NET Core (?) and Squirrel, all working together. Looks pretty cool, just pity the people on <20 megabit connections - these apps are getting pretty big.
CatLight is one of the apps that do that - https://catlight.io