Apple chose not to bring movable widgets and the App Library to iPadOS 14.0. Some theorize that Apple ran out of time. This may be true. Figuring out how to make various size widgets re-flow when you change an iPad’s orientation is no small task. But it doesn’t explain the lack of App Library.
My hope is that there is a much bigger change coming for iPadOS’s Home Screen—one that refines multi-tasking, app launching, and widgets into a more iPad-centric paradigm.