I'm familiar with this. I have rebinded these, but basically I use them everyday for tab switching, for example within 1 chrome window, of within 1 terminal window.
The reason I made this window-switcher is that sometimes I have something I know I opened a while ago, but I don't want to think about which app holds it, then use the macOS app-switcher (command-tab) to switch to that app, then select the tab/window (with the mouse, or by cycling alt-`).
I want a big mosaic with my windows, and instantly identify and focus on that window I remember the visual traits of.
macOS offers exposé for that purpose, but it is unfortunately not keyboard operable. Also I prefer the Windows approach of having a the thumbnails on a timeline so my eyes have some references instead of scanning the whole screen every time with exposé.