I guess this is a different take on the usual "everything is being dumbed down and I hate it" threads popping up lately, but there's a very clear reason content and playstyle nerfs are taking place, as well as the push for solo playability; they want to make the story experience smoother for new players. If jobs have a low skill floor, these new players no longer need to work too hard to hold up against better or more experienced players as they go through content and they can get the story much more easily.
This, I believe, illustrates why very few MMOs have ever tried a story-heavy model, and even less have succeeded. When it comes to battle content in MMOs, the success usually depends on the participation from all parties involved. When failures happen too many times in a single duty, given that it isn't endgame content, people will grow impatient and leave, and the new player who was struggling to perform is set back to square one and not able to continue with the story. Compare this to a single player game, in which whenever you die it only affects you and how many lives you have. You can get back up and try again without wasting anyone else's time, and do that as much as you need to before you clear it.
Initially the game wasn't really affected by this disconnect; back in the days of Heavensward, when the game was more niche, people were ok with jobs being the glorious messes they were, like SMN being able to place 4 dots or every job wanting to level archer for raging strikes. But then 2017 came, and the playerbase growth started to rapidly pick up. Because of this, the number of casual players greatly increased, and jobs were being streamlined in response. Some jank was still there, and while I honestly believe job design was just fine back then (sue me), there were still some jobs that needed some decluttering or there were people demanding it regardless. Square is catering to casuals before anyone else, everyone can see it, so that's how we reached this point after the massive player boom of 2021. By now I think the incompatibility between MMO format and single player story is too much to overcome at this point. No matter how they try to flatten the learning curve, there are always going to be players who don't know how to play near-optimally, or who actively refuse to do so and would rather be lazy or just outright grief.
Honestly, this game and its story would make a killer single player game, like a traditional Final Fantasy. It could even go the route of FFXV, the world is just so vibrant and could make a great open world setting. And honestly, at first I believe they were intending to replicate that with the ARR zones, with fates and instanced dungeons instead of overworld bosses and treasure gauntlets, but they promptly gave up on it as soon as HW came around. Their zone philosophy notably shifted from the world being where the action takes place to a narrative device. If we could revisit Eorzea in a future FF game, like how we got to revisit Ivalice, I'd be so down.