That is your opinion, but I disagree. Having no addons in the game would have made the game a way worse experience for all the players playing it through the years. There is a reason that almost all players used some form of addons to edit/personalize their UI. This is because blizzard made a terrible job designing the UI.
Addons are a big reason for the success of the game, as they came with some drawbacks (that are explained in the video).
Sorry but where did you get this? Most of the people that i’ve met all these years (inside the game) rarely have a problem with addons.
Yeah the problem is that addons are neither unfair nor boring. Everyone has the tools to not only using any addon, but also build anything he likes (and blizzard allows ofc).
Apart from being extremely hard and bad for the game to ban addons, imagine what ecosystem it would create:
Take DBM as an example. We know that boss do abilities in certain timer/energy levels. If you play without DBM, then your raid leader would find the timers that a guild that killed the boss made, and send it to every player.
Then each one would use either a program or physical stopwatch to track time and abilities.
Again bad example, cause there are some sports that allow steroids or other performance enhancing drugs. Each sport has his own list of substances that are not allowed and tested for (like blizzard does with the ToS and what kind of addons they allow).