I’ve never used a yoyo with schmooves, but it seems like the idea is have a high-walled design/look with reduced friction.
I’ve also seen a little discussion about whether the groove causes a change in air flow that affects the string during slack elements, but idk.
As far as reducing center weight, if that was the goal, it seems like the entire wall could’ve just been made thinner rather than just a groove, but that’s just me. Maybe schmooves give it a unique weight distribution & feel.
Here are examples of yoyos with response moats/schmooves for those interested: