The bike biz is very homogenous. Comparable money buys you comparable bikes regardless of what’s on the label.
If you want light, stay away from department stores etc. You need to go to a real bike shop. Even then, don’t expect much. Ruggedness and durability are generally seen as more important features. So-called ”race bikes” aren’t expected to see as much abuse as the jumps and tricks bikes and can be a bit lighter. But not as much lighter as your wallet will be after buying one!