Alt-Tab fade-in/fade-out feels sluggish
The fade-in/fade-out effect that's used when moving (using cursor keys, or a mouse) from one entry to the next in the Alt-Tab popup makes the popup feel sluggish.
(Same for the input switcher)
https://gitlab.gnome.org/GNOME/gnome-shell/-/blob/main/data/theme/gnome-shell-sass/_common.scss#L89