Niri implements a scrolling windowmanager like PaperWM instead of tiling like Hyprland. Tiling resizes your windows constantly, while scrolling only resizes when you want it to. If you keep opening windows, Niri opens them to the right of the last one on an infinitely wide workspace. Workspaces are organized vertically downwards. There’s no fixed number of workspaces, they grow on demand. There’s also a zoomed out overview showing you all workspaces and windows. Niri and Hyprland have some similarities though otherwise like lots of keyboard commands to move, resize, arrange windows.

Niri is friendlier overall I would say. It’s worth trying both since they are distinct.