Carbon rims [usually] are lighter than alloyed aluminum First advantage will be faster acceleration The next notable change will be ride quality Some carbon rims are stiff as hell, others give a more forgiving ride Perhaps if you identified what you hope to gain by a carbon wheelset ?
Lighter wheels take less effort and there is a significant weight savings with wide carbon vs alum. Another huge advantage is that they set up tubeless so easily vs alum rims with cutouts. If you ride low pressure (snow/sand) going tubeless is a must IMO. If you swap tires summer vs winter, the ease of tubeless tire swaps alone is a major selling point.
When talking 80 or 90mm wide aluminum tubed vs carbon wheels tubeless, you are close to 1/2 of the weight, which really transforms a fatbike into a much better performing rig. Tire quality is critical as well. There’s some garbage tires out there. Stay with Bontrager, Terrene, Surly and 45n.
Have a look at the DT Swiss BR2250, I converted my Ithaqua1 last year and went tubeless. Bike is now under 28#. The aluminum DTs are superb quality and comparable in weight to many carbon alternatives. Ride Fat!!