What you see as a trivial hour of investigation on a Striking Dummy, followed by having no surprises left to explore, can instead require some genuine amount of consideration for people who don't dedicate themselves to FFXIV the same way, don't seek external resources, or... etc. It's an entirely different standard to be judged against.
For a lot of players, especially when playing content that's already complex and punishing like Savage and Extreme (again, try to temper your own biases when considering how this content "feels" to the broader, average player), details as simple as:
- Adjust whether or not to precast Ruin 3, Searing Light, etc, based on later mechanic alignment
- Adjust your opener based on the Jobs in your party
- Make sure to get 6 GCDs out of every Bahoenix
- Don't spend Festers inside Phoenix if you can bring them into the next Searing Light
- Don't forget to Akh Morn / Revelation inside Bahoenix
- Don't forget to Deathflare during Bahamut
- Don't waste your Ruin IV, but also feel free to put it where it fits best
- Remember to insert 1-2 Ruin 3 hardcasts between "loops", or more if your party is intentionally drifting CDs and it's deemed productive for you to do so as well, rather than intentionally-desyncing; or if you're progging and trying to hold either damage or Phoenix for a specific segment; or if things are just buns-up and you'd rather hold burst until recovering; or etc.
- Make sure to choose your Gem order so that problematic casts (Ruby Rite, Slipstream) don't collide with movement pressure; Ifrit doesn't collide with bad times to pollute the melee zone; the boss doesn't move out of Slipstream; etc.
- Exploit the ability to move Ruins around to help manage problematic Gem phases
- Balance trying to keep Titan's high potency inside raid buffs vs. using its high mobility to manage encounter phases
- Use Radiant Aegis to help your healers / help survive mechanics, and don't get locked out of it at a bad time
- Try not to waste your Rekindle during Phoenix, if it can help your healers
- Weigh the trade-offs carefully if downtime forces you to choose between finishing Gems or leaving Bahoenix sitting off-cooldown
- Consider the possibility of truncating Gems without finishing them
- (etc.)
...are already plenty enough "meat" and "details" to track and adjust around, and feel like they have a "ceiling" to work towards "mastering" on any particular encounter.
It may not be enough
for you, but you need to realize that what's "enough"
for you may be uncomfortably over-the-head of the wider population.