The Ferrari 296 GTB weighs about 1500kg and the sports version 1300kg. For the cars YASA produces motors for it's much easier to increase the power to weight ratio by reducing weight than increasing power. I imagine an important design point for all of its components is to reduce weight.

I agree insofar as the motor is not a Big Ticket Item, opposed to ICE cars where the engine block is going to be 10% or more.

Tesla (I know) claimed a 30kg (?) weight loss on their Cybertruck (I know) just from moving their 12V systems to 48V, allowing for lighter cables at lower currents. Not all such potential is untapped, and my hunch is that there is more to be had with structural battery integration, battery cooling, and high voltage wiring.

Depends on your definition if significance, but I think they do. Every kg of useless weight you do carry, lowers your range. But sure, on its own it is not a magic game changer for heavy electric cars.

For light weight vehicles on the other hand, it might be.

If you put several small motors on each wheel you might get some extra weight gains in the form of less transmission needed. Cables weight less than metal structural bars. But yes you are not going to be 500kg lighter.

Weight reductions on an electric car are self-reinforcing. If you reduce the weight of a component, the battery can become (slightly) smaller, which again reduces weight. At a certain amount of reduction this will allow you to make the whole structure lighter, which will again allow for a smaller battery.

So yeah, weight reduction on EVs is great.