It probably wouldn’t surprise you to find out that workflows on iPadOS and iOS are better integrated than MacOS and iOS. iPadOS was derived directly from iOS and most modern iOS apps run on iPadOS. Many app run on all 3 platforms and that continues to grow with Catalyst now making that even easier but the interaction paradigms can be very different on MacOS. An app like GoodNotes on MacOS feels like such a bizarre experience where you can reference your handwritten notes but content creation makes little sense. Even apps that I think are very good on MacOS, such as Fantastical, just feel different and not as useful as their iOS/iPadOS counterpart.
The end result is a more fluid and less cognitively intense experience when moving between iPad and iPhone. Want to check your todo list? It’s the same icon on the same homescreen and when you tap it an identical experience. CloudKit is so good now that you can pick up your work instantly on the other device.
This was especially great when my days included meeting someone for coffee and just generally moving around a space. I could stop for groceries and if a work emergency came up I never thought “I have to get back to my Mac”. That said I’ve been noticing the seamless transition more while at home where I an more frequently shifting between work mode and home mode and the biggest difference between my computing devices are a keyboard, trackpad and the size of the screen.