That sounds like a great way to make a mess. Look at Microsoft's own apps shunning proper File dialogs and instead presenting a giant, bizarre pane of mostly text and a few crudely-drawn boxes in order to save a file. You have no idea what you're looking at or where you are in the file system.

Then there's the removal of title bars from Windows. You often have no idea what app you're looking at. Pull up a PDF in Acrobat and also in Edge. Now, at a glance, which is which?

Regressive garbage.