Oh, I see what you mean, using Catalyst to port the iOS version to the Mac and then sell it there as well? It’s a little more complicated than just clicking a checkbox, and probably would involve a few months of work for something of the scale Scrivener is.
And once done, the main question would be why? Why would anyone want to use the iOS version when the Mac version is available? Surely there might be a few here and there that do—don’t get me wrong—but reason enough to bring out a whole new product that now must be maintained going forward? As you can see, we hardly even have time to maintain what we have. It’s a very small shop.
At any rate, here’s that discussion which already happened, and a bit earlier but most substantially.