I am not as curious because we have WoW as an example, even though like you said casuals are the majority even in games like WoW that mentality has taken hold since it spreads like a disease if it is tolerated even to lower level content. You would occasionally see topics about some elitist complaining about the performance of someone in heroic dungeons which are equivalent to MSQ dungeons in ff14 where you can literally do them with multiple people dead, a more adequate example would be people demanding meta for a +6 key while people are doing 20s during that time.
The mentality that comes with said addons is my main concern.
You are correct, they will always exist, but I honestly dont mind them if they are used secretly by a tiny minority that has to actively hide from SE.
Right now SE might as well have given their approval when people watch streams with people using similar addons or even basic addons and never getting punished for it even though they are all against the ToS, the previous rule of "use it but be quiet about it" worked as long as we dont have streamers influencing thousands by using addons publicly like that and saying its cool. Because afaik only some JP streamer got banned, there's a ton of western streamers who used addons publicly and didnt get banned.
I will utterly and completely disagree with that, people usually end up tunnel visioning and having the addon or raid leader wake them up to the mechanic because you often see if the raid lead forgets to mention something many people screw up because they depend on addon/raid lead to tell them "Yo, mechanic inbound". Which imo is completely wrong, a raid lead should be there for when there's uncertainty and people have to make a decision quick, not to literally baby sit you and tell you when mechanics happen, that should be personal responsibility.
Which is a terrible thing because there's many mechanics that require you to track add positioning or some type of visual element that changes over the duration of the encounter that might come from some random direction, so if you are to respond adequately you need to also pay attention to it and not just forget it until the last minute call else you might not have enough time or space to survive.
This SERIOUS lack of spacial awareness is something very common in WoW's high end content and that is because people never learned the mechanic through in game visual signs to begin with and instead depended on addons or raid leads.
And its not just "oh our players are getting better", mechanics become far easier when you have a timer or unique mechanic announcing sounds, it literally is easy mode with them which results in dev having to make it even harder to compensate for the use of such addons which leads to more complicated mechanics and further problems, hence why such addons shouldnt be tolerated publicly, let them exist only in the shadows unlike know where they are literally public. And that will also hurt streamers who cant clear without addon help xd