I see a possible solution for what the OP wants but it would require this to become a thing.
1. Players who are just leveling and getting through story would no longer need higher level players to get through the story to their own high level.

Introduce a veteran mode to instanced content.

What is veteran mode?
Veteran mode is having every dungeon, raid, and rewards synched up to whatever the current game max level is.
  • A. Max level job gets to use their entire kit.
  • B. Enemy strength and rewards are scaled to the max level job.
  • C. Content could feel more engaging and stay relevant to a player who has progresses further.

The downside:
The duty finder would become a dead wasteland for players just trying to get through their own story and reach max level for the first time on a job. The new player would receive less mentoring or less angst from players expecting the newer player to get good fast. The community of noobs and veterans would be even more segregated than it is now.

If veteran mode was introduced, that trust and squadron system better be very good and be usuable throughout the entire MSQ for leveling players. Veteran mode would still not become as engaging as something designed at a higher level because the mechanics get larger in quantity the higher level you get. But at least things would hit harder and the people like the OP would get to use their entire kit.

If segregation is not a huge thing to playerbase and this happened.
Why stop there?
Just make veteran zones too.
Everything in a zone is upscaled to a max player.
Two zone types for each zone.
  • Standard: The normal zones we have now.
  • Veteran: The zones scale up to max level.