Maybe Apple is working to bring Xcode to the iPad in different phases, who knows. We may be currently at phase 1 with Swift Playground without knowing it. Phase 2 could build on top of Playground to make it more like Xcode but with support for a certain type of applications that can be build, tested and submitted to the App Store for release. In phase 2, only Swift and SwiftUI would be supported. This year WWDC could be the year of Xcode for iPad. This would be another pivot moment for the platform.