Wheel spacer?

I am re-doing my front wheel bearings. I’m trying to understand what spacer #2 in this diagram does. What’s the function of it? It seems like it just floats around the axle and all of the weight goes through the bearings.

https://www.partzilla.com/catalog/yamaha/motorcycle/2019/yzfr6-yzfr6kl/front-wheel

 

Without it, you wouldnt be able to tighten your axle without ruining your bearings.

 

Yeah that makes sense. I just found a similar explanation. It basically braces the inner bearing races laterally. I’m guessing the clamping force from the axle creates enough friction that the spacer spins with the inner races, so it’s not actually floating.

 

The inner races do not spin. Nothing that physically touches the axle should spin.