It could be useful to show two notes next to each other.
Roam does this well, Obsidian took it one step further by allowing a custom layout with many panes which is not necessarily very user friendly.
For me personally, just being able to split your screen vertically to open related notes next to each other would be great already. Right now I open two browser tabs side by side, which is ok, but certainly not ideal.
PS: This may have been requested already, but I couldn’t immediately find a post asking for this.