You don't have to have the sidebar chatbot thing. When mozilla added these AI features, after the update the browser prompted me to whether I want it or not, with the "yes" and "no" being equally easy to select. It did not add them without consent. You can disable all AI features altogether, or you can completely remove chatbot sidebar specifically (with 2 clicks) and have the rest of the features if you want them.

Gosh most of the time when I read people complain about firefox, it gives me the impression they have not even used firefox.

Firefox lets you disable all AI features with 1 setting switch.