To limit the range of motion and make it easier lol

I have long legs but pretty short arms so the trap bar can be more comfortable for me, simply because the grip is higher. I find the neutrl grip more comfortable too. I definitely think the trap places less stress on multiple joints. I also think the lift feels different, I guess because you are more upright you’re driving up at a different angle? That might only apply to long-leg people idk.

Comfort and stability...

It feels nicer

The trap bar is more leg drive than posterior chain. The traditional deadlift with a barbell is a hip hinge whereas the trap bar has a more vertical path. IF I were to use a trap bar I would use it to train legs and not as a hinging movement for the hips and posterior chain and spinal erectors.