One fun use of emacs even if it isn't your main editor is to use M-x describe-char to see what a character is. Can detect and describe obscure unicode, emoji, math symbols, zero width spaces, right to left text symbols, etc. I often use it if some text looks a bit off and I suspect something is hiding in it, or if someone posts an emoji in IRC and I can't tell what it's supposed to be (in part due to small size). There is also M-x insert-char to search up a character by name and then write it.

I learned of this by watching a Xah Lee stream once where he used it. There is a similar thing with the vim-characterize plugin, but I like that the emacs way is built-in and works everywhere.