There's more to binoculars than optics. Weight isn't a static thing, how the binoculars feel will also depend on their balance. I have some friends who just don't bird in the rain. This is the big bugaboo of weight and magnification. When binoculars are 10 power, all of the shakes and trembles of your hands are magnified 10 times.
Some people think heavier binoculars are easy to keep steady.
Birding optics involve compromise and trade-offs. My final pair of binoculars is lovely. With Nikon Venturer LX 8x42s, I got the quality optics I was looking for. They are a bit heavier than my previous binoculars, but they are so well balanced they are easy to bird with all day. They were also expensive, but worth every penny to me.