While trusts are godawful slow compared to a party of players -- by design; even if you want to go fast, they stubbornly refuse to use AoE abilities -- I admit I still like to run every dungeon with the Trust once, because watching the character interactions that can happen there, whether between each other or between the characters and the environment, honestly helped to flesh the Scions out and make them feel more like, in terms of the narrative, they were really there at my side through this journey in ways they hadn't been in previous expansions. I have a lot of favorite moments/interactions I've seen with the Trust NPCs in various ShB dungeons. So I absolutely get where OP is coming from on that "connection to the party members" aspect.

(Mind you, I generally only do it the once unless I have some second combination of characters where I really want to see whether they'll interact with each other or the dungeon itself in interesting ways. Because as mentioned, wow are the Trusts slow.)