The main features I use are

1. quick-select the output in the terminal (select files/paths, urls, etc and either copy or paste them at the cursor). This is very useful as you often don't have the foresight to pipe the command to pipe the output of the command to some selection mechanism and even placing text on the line-editor is not that easy by default.

2. view images (sixel or kitty protocol). This is pretty useful visual analog to cat that doesn't require opening another program and works over ssh. Also for video.

There are some other nice utilities for doing things like downloading files directly in the terminal (it2dl for iterm and kitten transfer for kitty).

kitty doesn't work out of the box on macos if I remember; you have to set configuration for option/command etc.