That anyone would think 2 years is a long time for a part not to need adjustment is a symptom of 21st century thinking surely. I'd also suspect you're not riding 100s of km of hilly terrain every week (I do, and have definitely needed to make adjustments, but no more often than on mechanical shifters).

2 years of no adjustments on any bike, is pretty unheard of, regardless of technology involved. Cables stretch, e-shifting gets rid of that issue... there really isn't anything to get out of alignment there.

I've been riding and racing bikes since I was 15 years old and I'm nearly 50 now.