Why are NPC parties so bad?

[Thangil]

The reason trusts are bad is because they are designed to be bad to actually encourage you to play with other people because it’s an MMO

Trusts are more insurance against the game dying in the future or if people are crippingly antisocial, in general they expect you will run with other players which is why they leave the trusts as being 30-50% worse than an average player. To actually encourage you to play with other players

I have ABSOLUTELY NOTHING against playing with other people. The issue here is not about that. The ONLY reason I wanna do dungeons with NPCs, is to eliminate the wait time, nothing else at all.