As a Magnet user, I feel there is a big difference between windows organizing that Magnet/Rectangle does and Window tiling that the OS supports. The window organization can help you have many windows floating at once but still not as good as snapping a window properly in one place.
But again, to each their own. I am sure Magnet/Rectangle users will still want to have 4 windows floating around - something that macOS is limiting to just 3. Thanks for sharing this story and bringing out all the necessary points!