I'm relatively new to this, and part of my approach is to recover the natural abilities that Western comforts have cost us: full body flexibility, the ability to squat comfortably flat footed, the ability to sleep on the ground in natural positions, etc. In the long run, recovering these natural comforts seems better than packing "lightweight" comforts along with us.
Bare feet are Nature's warm-weather moccasins. Great grip, too.
People all over the world sleep just fine without sleeping pads. Backpacking uses a lot of energy and most people don't sleep well. I'm convinced that that can be rectified without carrying a mattress of any kind.