A321 flight crew reported a ground conflict with a baggage vehicle during taxi to the gate.

Narrative

Baggage truck driver hazarded him/her/their self and our aircraft. Ground cleared us to [parking via Taxiway 1]. Approaching [parking]; Ramp cleared us to the gate via the left-side. Since we were preemptive with our communication to Ground and Ramp; we needed to slow their aircraft's taxi speed. As we approached the non-movement area threshold; a baggage truck converged with the aircraft from the right (driving east to west along the non-movement area line). The left-seat pilot cleared the aircraft's left side; and I cleared the right; noticing that the baggage truck wasn't slowing. Realizing that the baggage truck wouldn't yield to the aircraft; I instructed the left-seat pilot; 'Hold.' It didn't register immediately; requiring me to say it twice more. The left-seat pilot seat placed the thrust levers to idle and applied the brakes forcefully; prompted by the urgency in my voice; and I turned off the taxi light. The baggage truck passed in front of the nose (underneath from our perspective in the cockpit) so close that we had to sit up to see him. This was the first time the left-seat pilot had been able to visually acquire the baggage truck driver; who then made a right turn to travel parallel to the left-side line and the gates and disappeared into the terminal. The driver seemed unaware of the aircraft's motion and proximity. We would have struck it or worse if we had been two seconds delayed in noticing the baggage truck and/or stopping the aircraft. The driver hazarded the baggage truck; his/her/their own life; and the aircraft.A lack of situational awareness on the part of the baggage truck operator. The aircraft was in motion with the taxi light on; and the operator was looking straight ahead and didn't seem distracted nor did he/she/they demonstrate any sort of recognition or care for his/her/their misjudgment when the aircraft came to a sudden stop.Safety is paramount and getting runover is tragic...and avoidable. Ground personnel must maintain their situational awareness. Ground operations must emphasize the extreme hazards posed by aircraft operations and that patience should be exercised when moving about the ramp. There must also be an emphasis placed on expressing the need to give moving aircraft the right-of-way due to inertia.