“This becomes even worse if the third party is supplying a cross platform development tool. The third party may not adopt enhancements from one platform unless they are available on all of their supported platforms. Hence developers only have access to the lowest common denominator set of features.”
Talking about 3rd parties, but the same problems seem to be limiting the cross-platform Catalyst system as well.
SwiftUI seems like a better approach if only because Apple is trying to make it a unified platform, instead of abstracting on top of two different platforms.