Despite this not being FOSS like GIMP, I think it's great that there is at least some very viable alternative that can run on Linux even with some workaround, for free (besides Photopea).
While I agree with a native port. I think work around like this is also good too since it shows demand. I mean it’s why there is a good level of hype around Linux Gaming thanks to Steam and its Proton compatibility layer.
So long as Affinity isn’t blocked from running like what adobe does. I think this is fine until a universal binary is possible.