A lot of boss mechanics are scripted to occur at a certain time after the encounter starts, so having predictive callouts from ACT wouldnt be unheard of. Beyond that, ACT is supposed to pull info from the combat log.
For someone who actually wants to know their performance in a Savage setting, a dummy showing that they do "enough" damage is not satisfactory. That being said, it's easy to parse well on a dummy where you stand still for 3 minutes versus a fight where you have to perform a rotation while also being mindful of the mechanical dance. And, again, it doesn't take into consideration things like party buffs. So the number is inaccurate.
SSS is not a satisfactory measurement of your performance.
Yet, it is a good gauge of knowing your rotations. Something that is sorely needed these days. Sure, it may not be able to show how you perform in content with group buffs, but if you can't do your rotation on a dummy, you sure as heck can't do it while mechanics are happening, and no amount of party buffs will help you then.
It also helps that if you can practice your rotation on a dummy, it then becomes muscle memory, which makes it easier to do while doing mechanics. You stop having to think about what the next step you have to do while playing your job, and can concentrate more on the fight.
Playing devils advocate here... but in regards to FFXIV this is actually a player imposed term of acceptability. SSS is the marker to whether you are capable of outputting the required dps.
Personally I don’t care whether someone parses or not assuming it’s for their own info or a static where everyone is working to better themselves, but in a pug that info is often used to insult not teach so I dislike them then. I do care about mods/Addons/programs that tell to react. Those are bogus and a crutch imo. Ultimately, whether you like to parse or not is irrelevant. FFXIV tos specifically states no 3rd party programs. Get caught using one well you accept the consequences.
The irony of this is that it may tell you that "something" is wrong with your rotation if you fail to clear it, but there's no way of knowing what that something is since the dummy won't tell you. Meanwhile, a log that has a cast-by-cast of what you're doing can be given to someone who knows a role well, and they can pin-point exactly what you're doing wrong.
I've been in one Savage PUG group where people insult others about their numbers (correction from "never" - there was an A10S group I joined back in Creator that had someone being salty about it...and the group kicked him for it). Most groups I'm in, even when there's clearly a member underperforming that one would a parse could see, people generally don't say anything. But we're discussing anecdotes here, not facts.
For anyone who wants a clear picture of their performance, SSS is not satisfactory.
Except, as has been stated, parsing is technically against the ToS, so you would have to look outside the game for help anyway, in that regard, and ps4 players would especially need help there. Someone who fails the test could also look up guides or talk to friends, without even needing a log.
A log may tell you the fine details, and if someone made small mistakes, sure. You don't need a log to help someone who is doing something fundamentally wrong, like not applying dots, keeping buffs up, or using completely incorrect skills, like thunder 4 on single target, or spamming blizzard.
Again that is player imposed and not what SE has deemed necessary hence why we have SSS and not permission to use parses. Ultimately it is their game and we deal or we don’t. I do agree that SSS is not adequate to display if you can meet the requirements if you are moving dodging etc and if you are trying to push your limits, but that is not the bar that the devs have set.
I don't know of any game that tells you how to optomize openers and rotations, xiv is not alone in this regard. To expect this seems rather silly imo.
The game provides enough information from tool tips to be able to put together at least some semblance of a rotation, and you can formulate an opener based on those tool tips as well.
I mean, I've never looked up a Bard guide, hadn't played it since I got it to 70 after stormblood, and you can look me up. None of the jobs except mch and smn really need guides on rotations and openers. The only thing Sam benefits from is CD alignment depending on skill speed, so in that regard sure.
Part of the problem is people just don't even try. How else do you get level 70 players in o10n who run away with stack markers multiple times.