I'm using 3 Audis for comparison, and probably won't help much.....
I had an A5, albeit for a very short time, that was second hand, so had the benefit of about a year's wear and the leather and the seats were really soft. I got rid of it because I didn't like feeling like I was driving in a comfy armchair.
My wife had a TT from new, and by the time she sold it, after 3 years, the leather was still as stiff as the day it arrived, the seats were hard and I found them really uncomfortable.
My father had an A4 for about 7 years, and again, the leather stayed in the same condition as when it arrived, so was quite stiff/firm.
I suppose I'm saying that the leather is very good quality, so might not change much from how it is now, but it's worth going back to Audi if you're finding it uncomfortable, they might be able to do something?