Looking at my own installed extensions, I have a password manager, Privacy Badger and Firefox Multi-Account Containers, which I suppose is the three I really need. Then I have one that puts the RSS icon back in the address bar, because Mozilla feels that RSS is less important than having the address bar show me special dates, and two that removes very specific things: One for cookie popups and one for removing sign in with Google.
The only one of these I feel should actually be a plugin is my password manager. Privacy management (including cookies), RSS and containers could just be baked into Firefox. All of those seems more relevant to me than AI.
Maybe adding a GreaseMonkey lite could fix the rest of my problem, using code I write and control.