Seems that it is doable:

https://github.com/PixiEditor/PixiEditor

However, I think without having the burden of legacy code and APIs it is a bit easier to accomplish. Probably paint.net has been targeting Windows platforms from the beginning and making it "Linux compatible" has not been a big effort but more a side effect of fixing some stuff and wine generally being awesome.

I personally would love to see commercial editors like Affinity Studio targeting Linux. While solutions like Krita and Gimp are great, it did not really click for me. I'm using Gimp, but somehow I often find myself seeking for how to do easy tasks that should be more intuitive.