Switched workspaces I know what is on each workspace, I can switch to it, see what's there. But the Niri approach, I have to scroll through the space to see which windows are actually there.
Overflowing Gimp onto another workspace because of this is the main cause of workspace spam that a scrolling WM solves.
If you're working on more than one project (so, workspace 1 2 and 3 are fully utilized), where does this overflow workspace even live? And what if each workspace also needs its own Gimp instance?
There are certainly solutions to this in every WM, but the scrolling WM solution is a really simple one that never makes you ask the question of where to put something: workspaces have an offscreen overflow area.
Another way of thinking about it is: sway would be instantly improved for me if it also had a per-workspace overflow area, like maybe if every workspace had its own scratchpad that I could tile windows on, and I could reach it by moving focus into it kind like moving between monitors.
If I need a Gimp in every workspace I just open a Gimp in every workspace where I need one. Or even customize my Xmonad to show specific Gimp instances on select workspaces.
Again, how does the scrolling layout do me ANY favors here?
Sure, Niri takes away the question of where to place it, but it definitely doesn't help with "Where the fuck is that one window I opened and how do I find it?" I'd rather just quickly select all my workspaces in the worst case than selecting every workspace and THEN scrolling through all the windows.
If you really need THAT much overspill on a workspace I would personally rather stop and re-evaluate the workflow instead of just spilling tons of windows all over the workspace.
It feels like if you'd sit down and re-evaluate the workflow and the setup, those problems could be solved almost without a WM.