I am sure the 2x9/10 would not work for me. I already did most trails on the middle ring, using exactly the full range of the 11-34 cassette. I just took the big and small ring off without noticing! In Italy I often ride on the the big ring on the road (up to the 11 rear) and on the really steep uphills off-road on the small ring (and using the 34 rear). In both cases I wouldn't have any thing better with a 2x setup. Maybe in Begium, were the hills are bit steeper then in Holland, but less the Italy, but to make a bike especially for that.....
Again, it fully depends on the terrain and how safe you want to be. A 3x setup will work everywhere, but if you mostly can do with 1x, if youcan't do it, you can always walk! I have to say you will learn to ride differently, more anticipating. Will I did my local trail a long time ago only on the granny ring, because of lack of power, I can now do a double round on my singlespeed (38/19)!