My folk theory about bike weight is in terms of ranges. More than 30#, all kinda feels the same to me (heavy but stable). Between 30 and 25#, I really can’t tell the difference between them, though they certainly are more agile than the heavy ones. Less than 25# is best, usually quite a difference in climbing. My favorite riders are all around 20-22#. I’ve had a few sub 20# bikes, including a Ti bike, and that one felt quite dead. So it’s not just the weight or the material, but geometry, wheels, other components, my fitness level, etc.