AdGuard is for things I take off the home network, for example when I'm at work. It's true I could use AdGuard for both scenarios but I do like the additional visibility and configurability Pi-Hole provides.
I basically have all my devices use it when I am on my network, and when I am off my network, my Wireguard connection (or Tailscale depending...) uses my home DNS server.
I basically have all my devices use it when I am on my network, and when I am off my network, my Wireguard connection (or Tailscale depending...) uses my home DNS server.