I might give Niri a shot at some point, but yes, this is my thought too: this is more or less the same as having multiple tabbed panes, which enables the grouping GP refers to.

I was running i3 and sway foe years and tabbed tiles never really clicked for me the same way scrolling did. The first time I used a scrolling WM (I tried on of the plugins for sway or hyprland IIRC) it was an immediate revelation. However the sway/hyprland version were always a bit quirky, while niri "just works".

For those on older niri versions I have to say the "zoom out" overview feature is definitely worth the upgrade. As another poster said it really fixes the one issue on scrolling/ tiling wms, which is getting lost.