Earlier quoted context omitted.
You have to give up trust in some way. I trust extensions running on all websites less than I trust a mitm proxy, because the mitm proxy doesn't have the ability to run code in the browser process itself. Its capabilities are similar or even higher and unlike intentional TLS mitm attacks, addon redirection is near impossible to find in the browser UI. Reading through the code I see very little in the way of webPKI nu…
I use mitm proxies for my research, and very much understand their purpose. what I am objecting to is using it as a general purpose privacy policy network filter. That is not what a MiTM proxy should be used for. The mitm proxy can inject js into the stream and fake any origin. At least the extension has limits of what it can access, and the code is fixed, unlike a proxy that can say something is anything from anywhe…
I think mitm proxies should be used for whatever people find them suitable. I don't have a problem with this use case, especially as this is clearly something you will only get working with a moderate understanding of the underlying concepts.
Tools like Privoxy have existed for years and I don't know why you wouldn't trust a proxy over an addon. Just don't set it up for other people who can't make the risk/reward judgement (though the same goes for adblockers and other extensions).