Including an export in .profile does not update path after login

Question

I installed Kali Linux v2020.4 using i3-wm and have updated .profile [below] to include an exported PATH, as I assumed updating .profile would impact all shells (sh, Bash, Zsh, etc.).

After logging out/in, I'm not able to run a script that exists inside Desktop, but if I run source ~/.profile, then I'm able to execute it:

export PATH="$HOME/Desktop:$PATH"

# if running bash
if [ -n "$BASH_VERSION" ]; then
  # include .bashrc if it exists
    if [ -f "$HOME/.bashrc" ]; then
      . "$HOME/.bashrc"
    fi
fi

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
  PATH="$HOME/bin:$PATH"
fi

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/.local/bin" ] ; then
  PATH="$HOME/.local/bin:$PATH"
fi

• This is strange behavior to me and has only occurred using Kali; I have no ~/bash_profile, and don't want to include it in ~/.bashrc, as I want it to be available for all shells