The main difficulty I see in these "RETVRN TO SOVL" things is not the window-manager or desktop itself but the UI toolkits for the applications. GTK2 had so many excellent themes. Now GTK or libadwaita seem designed to resist themes and introduce constant breaking of selectors or widgets or whatnot. I believe they griefed the themers into just giving up. I have less knowledge about Qt, but I assume it's probably the better pick these days.

To say nothing of client side decorations, which diverge the user interface among apps and remove control from the user to globally customize some aspect of their application window management/theming.