Trusts and squadron

[Balipu]

I think the purpose is different.

Trust is there to clear MSQ duties so that you don't get stuck with 30 minute waiting times with your DPS class.

Squadrons are there to help you level your grand company rank.

Chocobo companions are there cause they are a discarded prototype of later systems (diadem, hunting logs, guildhests, normal mode trials, base classes...etc).

[Beckett]

Squadrons are there to help you level your grand company rank.

Yeah that's all they are now, but they were marketed as a system to let us do dungeons without having to queue for the DF. A system that would get improvements and new dungeons added to it over time.

I'm not quite willing to call it dead content yet, but the fact that they're introducing a new type of NPC companion after updating Squadrons once once in 2 years, makes me think that they're going the way of the chocobo.