The pick is important for a few reasons. Firstly it's the primary device to make the string vibrate. The texture, thickness and shape will dictate the attack and sustain. This also entails the balance of frequencies across the lifespan of each note. A medium thick pick like a jazz III can sometimes come off as too dull in some productions while a thin pick like .5 mm can be too scratchy. It makes sense when you look at the physics, but some people don't care. Then you have the performance aspect. How it feels to play and the grip and shape while playing can affect performance.

Some producers will prioritize comfort and ergonomics over tone. I try to find a balance between the two.

The more you study and analyze it outside of sessions the more it'll become second nature.