Honestly I think we need something like a training mode for people on savage at the very least. The problem is I'm not entirely sure how they manage to do that. A lot of games that do challenge mode content simply increase the frequency of attacks done in a normal version of the fight, but savage in FFXIV has the attack patterns being completely different and often hidden. Ideally the training mode should be the normal mode of the fight since otherwise the dev team would have to implement a trust system just to have a learning mode in savage, or make something like a normal mode, hard mode, and savage mode of every single fight. I'd probably be down for story mode, hard mode, and savage mode since it would let them keep the normal mode mechanic design untouched. It doesn't fix the accessibility issue when people are through the hard mode and just go strait for the savage mode, nor does it address the problem of savage mode stragglers that get stranded late in the season or come back from a break.

Like it is 100% true that using pure gear level is not sufficient as a catchup mechanic for end game. The trust system does have potential to help solve at least a few problems in this regard, but savage mode... I'd almost say they should make the gear pure item level boosts and let people dye their normal mode gear. Yeah you get more people into doing savage so they can glam, but that crowd is not made up of people that are doing this for challenge running, which is the whole point of this kind of content.