Opening and closing many workspaces in i3 can lead to gaps in numbering.
Instead of rearranging them yourself, you can have i3-auto-arrange do it for you.
This script is available as an AUR package.
You can use an AUR helper such as yay to install it:
yay -S i3-auto-arrange
Or, to install from source:
git clone https://github.com/denis-ismailaj/i3-auto-arrange.git
cd i3-auto-arrange
makepkg
sudo pacman -U i3-auto-arrange-*.pkg.tar.xz
Note
i3-auto-arrange depends on jq in order to parse the outputs of i3-msg
i3-auto-arrange is most useful when used as a keyboard shortcut.
To do that, open your i3 config file:
vim ~/.config/i3/config # or ~/.i3/config
and bind your preferred key combination to running i3-auto-arrange:
bindsym <key combination> exec i3-auto-arrange