As I said before, if someone bought a skip, then the expectation should come that they still need to learn the game. The game at level 100 should not be designed around people who effectively just started playing, they are outliers and the skip even tells them to start with the basics before jumping into content.
When I say that it is fun to optimize for uptime and mistake-less play, that is very much subjective. Which is why the option to not do that is there. Some people don't want to optimize, and that's fine. They don't have to, the content is just as clearable if you have 100% gcd uptime vs 20%. It just takes longer, but not as much as you think. If people find the content too difficult, I doubt they're the kind of people who enjoy optimizing anyways, as (this might be mean) an optimization mindset requires a desire to improve at the game. Some people just wanna see the cutscenes and get the pretty glam. But unfortunately, for a reward to mean anything it must require some effort. That is just a fact. If people want rewards with no effort beyond paying a monthly sub for the game... that sounds more like gacha than an enjoyable game.
(Sorry, I'm replying to your responses in order, but editing the quote reply on mobile is a pain)
I don't really know what instant death mechanic in dungeons youre referring to. Most times you get either a stun, or a vuln and some heavy damage, but I cant remember anything that just outright killed me in one shot. Apart from maybe the final boss of the circus dungeon i cant remember the name of? Something dreadwalk.
The thing is about saying 'I accept this is a problem for you, but not for me' is that this person, OP, is trying to get the game changed for them. The fights being too easy was a problem for me, because I dreaded doing them. Them being more challenging gives me something to do, but they still aren't like, overly punishing so much that I need to fixate like I do in extreme or higher content. I was so happy going through the story and I couldnt just turn my brain off for every piece of content like Endwalker, and it boggles my mind that people want it back. Because I wasn't a good player at the start of Endwalker, I was still casual. But i kept losing focus midway through and eating shit because things were just so boring. Dying because a fight is hard is one thing, but have you ever died because you started zoning out bc of lack of fun? Of course, the beauty of it was... I just got raised and got back into it. Because ultimately, I feel like people miss a big point. Dying is okay. Missing damage is okay. Wiping is okay (especially with the change to shortcuts in dungeons). This aversion to all failure points as OP seems to advocate for is part of why even the devs admitted that EW was a step too far.
As for AST... if you like, I could teach you. I havent played the class beyond 92, but not much has changed except for the cards, which I'm already familiar with. I'd be happy to keep the job alive, even if I end up straying away from it.