There are a few add-ons I would very much miss were add-ons disallowed, such as Postal and some wardrobe helpers. But for combat-related add-ons I've just removed them and enjoy the game without them. I still hold on to DBM but could probably do LFR without it so I wouldn't miss it, and I'm long past using DPS meters because I care not one whit how much damage I, nor anyone else, are managing.
But then, I don't do any of the top-end competitive stuff so I can play like this.