I added vim-fugitive and it was super slow — like, 2-3 seconds delay to do any command. Turns out it spawns the “shell” to get anything done, so my fish shell which takes a couple of seconds to start because of having asdf around — was slowing things down.

After adding:

# Anything beyond this point is not executed when fish isn't run interactively, 
# such as via `fish -c '...'`
if not status --is-interactive
    exit
end

Yeah, there's a few programs which shell out. I can't believe how slow your fish is.

My fish was that slow on OSX (for the short amount of time I was forced to use it), totally fine on every Linux machine. Also every program (like nvim) took ~1+ seconds to open due to some new OSX security thing at the time?

I traced the fish slowness to the asdf package manager.