Well, since WotlK is the example used in this thread, I will draw from that.
In 10-man IC, the easy raid shared the story with the harder 25-man IC raid. An easy mode coil would supposedly operate under the same premise. The easy mode coil would not only share the story, but the gear look as well.
In every thread about raid rewards vs ilvl110 hunt gear, people highlight the rewards from raiding in this game. Usually the list of raid "rewards" are as follows:
BiS
Vanity of HA gear
HA weapon
Satisfaction of raid clear
Adding an easy mode coil would further undermine the raid rewards. People from the easy mode of coil will get all the looks of HA gear as well as the satisfaction of the clear. That would be fantastic for them I am sure; however, how rewarding is the story going to be in harder coil when you are likely to see it in easy coil? Raiders will raid easy coil just for the gear bump to do harder coil. You could see this similar behavior back in WotLK where people raided both 10-man and 25-man before the combined lock out. People would use the easier raid for a gear bump for the harder raid.
Adding an easy mode would make the rewards from hard mode even more trivial. The only rewards left, after the 1st clear, would be:
HA weapon
BiS
Both of which are RNG dependent. There are sooooooo many raiders with get neither BiS or HA weapons. Those raiders will have essentially cleared the SCoB over and over again for no real substantial rewards.
That would be the big difference, the harder version of SCoB would lose even more incentives to be completed. If completing something just for the sake of completing it was reward enough, brutal coil would be vastly more popular than it is.
Then do raids? All the content you described is casual content aimed at casual players. A casual player plays casually for one reason or another. Why do you want a SCoB equivalent of ST? So there is another four bosses you don't care about?
Raid content has a long lifespan because of lockouts and RNG. At least half of the assents in the SCoB are recycled, so I am not sure what you are talking about when it comes to that. If players want more than "auto attacking" then they should strive to raid. There is also EX primals that players can take on as well as EX moogle. You are intentionally simplifying all the content in the game to support your argument.Meanwhile, raid content has a long lifespan due to constantly dropping relevant gear and more importantly, is intricately designed and one of the few pieces of content that hasn't used aggressively recycled assets since 2.1. You get at least three new encounters every patch to boot. It should certainly be more (why the hell aren't the raids fully fleshed out dungeons, I swear to god,) but it's still more than what you imagine all the 'non raiders' getting, which is some stuff to autoattack for a week and then log off. If they're lucky, something to autoattack for three months (hello, relics).
Also, the SCoB fights are not well fleshed out. I don't think you have done turn 7 where you have to sit and wait for up to two minutes (holding dps 20 seconds here or there to make sure you actually have a voice to stone a renaud) at times because the fight is poorly designed.
The same thing happens in turn 6. You have to stop attacking the boss completely until the 1st honey is eaten. Otherwise, there is not enough time between the 1st honey going out and the devour that comes up after.
The same is true in turn 8. You either hold DPS or start dealing with allagan field much earlier in the fight.
That's why you guys get ST. If you don't want to raid in a static, just wait for echo nerfs and go see the story in duty finder groups. You're sub fees don't guarantee the ability to see all the content. Stop acting as if this game needs to hand you everything on a silver platter.Besides, not everyone who raids does or desires to do so at the weekly static level.