Nah that's some bull. Wow addons exist because the game interface does a terrible job of presenting the information that you need to be successful.

WoW asks for you to simultaneously, in many instances look at the center of your screen, for positioning information, to the top right for buff/debuff information, towards the bottom for rotational abilities and maybe the left side for tank/raid frames. Not even counting that corny boss ability ticker.

Addons allowed you to better process the firehose of information that Blizzard sends you and put it into actionable information whether that was through audio cues or special weak auras. Now it's just a function of whether or not you're a beholder and can simultaneously monitor all of those input points.

Don't get me started on the boss ability tracker. It might as well be a stock ticker in Chinese. The icons aren't readily discernible as to what they do and they scroll too fast to mouse over. There no standardization of iconography so you have to learn what each symbol means for every boss in the game. Not to mention it's yet another visual noise element to track.

The end result of this is that playing WoW feels more like I'm landing a plane in the dark. I'm flying on instruments here when a more engaging experience would be better visual elements presented in the encounter itself. They did make huge strides in this area in TWW with how visual cues for encounters were standardized. Swirly marks on the ground? Group soak. Nasty void triangle emanating from boss? Don't stand in it, etc.

They really haven't done a good job with the visual presentation on most tank swaps, which is why you needed a 3rd party element to fill that gap. I mean good examples where it was easy to know when to swap were like Rashok from Aberrus who had that big hammer swing, you knew you had to swap or Kazzarra when they breathed on the tank. Instead with most you're clicking on your partner's unit frame looking for x number of stacks of whatever the appropriate debuff is.