The main reason is that it lets me access my home network. So if I want to watch a movie or something I have stored on my NAS, I can do that without exposing that service to the internet. Or if I want to Remote Desktop into one of my computers.

I used to use the AdGuard app on my iPhone, but 1) I found for whatever reason it didn’t seem to work as well as the standalone self hosted version. The way it works on phones is that it does some sort of local VPN trickery, and for whatever reason it’s like it would temporarily stop working. Who knows. But 2) now I just have a single instance of AdGuard to manage and get its benefits on all my devices. I don’t need to maintain lists or rules for the one running at home and separately maintain rules in the phone app version.