It’s not, see above. Plus it might not weigh was it does haha
Carbon fiber parts can be made really lightweight because of its strenght, but a very thin lightweight carbon part would not be particulary resilient to shocks and blows - it cracks, the relative soft and thick plastic parts dont. You could make a thick and strong carbon part, but then it would not be lightweight - it would however be quite expensive, probably cost as much as the saw.
But if you want a Stihl replica in its rightful colors - I guess you can now buy it ready made and then buy all the plastic in orange. Or you could do that with the 372 replica, that would be awesome - it would be a Stihlsky 372.
But I see all this talk about carburettors and caber rings, I have a 038/381 replica that I have made from parts all around the world. I started with a kit and I used it pretty much and relatively hard - because I used it to mill, lots of hours running at full throttle continuously.
So what became evident was not problems with carburettors and caberrings, it was the little things that was made of inferior metal alloys; like clutch springs, chain adjusters and guide bar bolts. Oil Pumps that needed to be re-made because its made too inaccurate and coarse, so that it leaks more than it lubricates the chain.