[Lammy]

Per-app mixing on the first-level menu. I like SoundSource on macOS for the same reason: https://rogueamoeba.com/soundsource/

[accoil]

I right click the volume icon in Windows, select "Volume Mixer", and it gives me per-app mixing. Which I guess is an extra click, as with eartrumpet you can access the mixer with a single left click on the icon.