What would happen if you configured manual network and gave it a fake DNS or sent it over to PiHole for example? Wouldnt there be plenty of ways to capture the

What would happen if you configured manual network and gave it a fake DNS or sent it over to PiHole for example? Wouldnt there be plenty of ways to capture the traffic and stop it from going where it wants to go? I would think the tech savvy folks on this site would be able to figure something out if it is a big enough concern of theirs.