Why isn’t the third party software ban enforced?

[Sotaris]

I learned today that people can install plugins for third party software that give them VISUAL and AUDIO notifications for things like Dots and spell cooldowns, and what the boss is going to cast next, making their rotations exceedingly easier to keep up during busier fights. Why is this not considered cheating? This puts me, a console player, and any PC player who refuses to break the rules, at a SEVERE disadvantage. Why isn’t this considered cheating and/or botting? It literally screams in your ears what to press next for your rotation and where/when to move. That’s cheating...or maybe I’m missing something?

That's been around for many years. It ain't news.
And they will always be there as SE won't scan your PC cause of privacy.

Also they don't hurt anyone or breaks the game for anyone.
There is used to be a visual call for one of the Ultimate fights and they patched that.