I think that tool exists in some form already? Maybe its not perfect but uMatrix is a pretty powerful filtering tool. It gives you the option to block these thi

I think that tool exists in some form already? Maybe its not perfect but uMatrix is a pretty powerful filtering tool. It gives you the option to block these third party domains - think of it as a firewall for your browser. Its built by the same person who made uBlock origin (which can actually have the same functionality I think).