Yes, they are fundamentally different in a way (although you could still keep the same layouts with Scrolling WMs). Scrolling WMs are a lot more useful for laptops, where the screen area is limited. It replaces the need for multi-monitors for me and that's quite revolutionary.

You can also use workspaces with a scrolling layout, you keep the advantages of both, and you don't need to keep on resizing/moving windows because they are too small.

When I moved to Hyprland after having tried almost every DE and tiling WM, I had to write my own layout plugin (hyprscroller) because of how much I missed PaperWM.

If you moved from classic DEs with floating windows and lots of mouse to a tiling WM, scrolling adds another advantage. You can even ignore it and use it as a classic tiling WM, but you also have all the advantages of scrolling once you find a use for them.