I want to point out that by downvoting this, you're reducing the visibility of the post for other people, therefore making less people informed of the change.
"Don't worry, we're going to open source Pocket and make it optional any day now."
- Mozilla Corporation (note: not Foundation), 2017
Firefox, tell your creepy little friend he can get the fuck off my property!
It's an add-on, not something baked-in the browser. It's not on your property at the first place, unless you choose to install it 🙂
For now, but one day Firefox will try sneak him into my house and hide him in a cupboard untill squatters rights kick in.
Even they choose to do so in future, usually there always is a about:config entry to disable it.
I've got them here: you're done.
You have to go out of your way to install ("enable") it.