The user interfaces for different platforms have to be different. Otherwise you end up with Skype 7.x, where we have a UI on the desktop which has been designed for a smartphone.
Low pointing accuracy on smartphones means large targets and huge icons. Short conversations on smartphones means lots of space wasted on speech bubbles. Likely content on smartphones means emojis pop up when you're sharing code snippets, making them unreadable. Restricted input methods on smartphones means ignoring platform conventions like Ctrl+B for bold text.
Conversely, try getting 3DS Max 2017 UI onto a smart watch. Regardless of compatibility, it's simply impossibe.