Although very functuional, weight was not a concern when the componets of your bike were chosen by diamondback designers. the focus was to meet a specific price point.

your crankarms are steel instead of aluminum. as are your handlebars.

your off brand suspension forks, suspension seatpost, and adjustable stem are quite heavy im sure compared to more expensive, purposely designed to be lightweight components.

I would not concern yourself with trying to upgrade this bike to reduce weight. It will be very expensive for seemingly minor reductions. overall it will make a difference but at the cost of 2x what you paid initially.

Ride her and enjoy her. If components break and you decide to keep this bike then you may want to purchase lighter replacements or upgrade the bike completely.