Catalyst doesn’t do much to help translate their iOS designs into Mac native elements. The enforced 2/3rds UI scaling sets an app two steps back from the get go. Most UI controls require manual customisation and reimplementation to make them look and act like their macOS counterparts. Some elements like sidebars do transform their behaviour when running on the Catalyst idiom, but the Catalyst stack seems unfinished as it doesn’t accurately recreate how an AppKit source list works. It is just wrong.
If you use AppKit, you can make a bad app. If you use Catalyst, you can easily make a bad app. At the same time, Catalyst is attracting developers who cannot justify to allocate resources to Mac-specific work. That’s the point of it: to bring iPad apps to the Mac with little effort. And so, the combination of cause and technology stack almost always results in a bad-to-mediocre final result, almost by definition.
Being successful on the iOS App Store is hard enough, a platform with a billion active devices. The scale of the Mac App Store trails by orders of magnitude. As long as that remains true, most developers will only be able to have a Mac presence through shortcuts like Catalyst, and that means app quality will generally suffer.
I don’t blame any third-party for making these choices. It’s basic economics. I am guilty too. I am sad that Apple — the platform owner and biggest company in the world — is leaning on Catalyst so heavily, and not even setting a good example in the process. For the Apple Developer app, they have tried to make a Mac navigation structure with multiple columns, which is nice to see. But that’s basically where my compliments end. I guess you can say that it is better than nothing.