The elephant in the room for big CAD/CAM apps is dockable widgets, where (for me personally), the "standard" is how Visaul Studio does it.

Even Qt, with it's built-in widgets is not enough (e.g. no multiple widgets/windows in non-main window), but there are some extensions/libraries/hacks to go around.

Recently, few years ago, imgui got proper support for these too. And flutter has one or more design docs around it - e.g. multi-window support, which might be the stepping stone to these.

Desktop apps are always going to be important in this space. Our game editor (Radiant) relies on this functionality when you use two, three or even more monitors.