> I'm not getting why this is suppose to be "hard".
Because that's not what's hard. Explaining the physical processes of the brain is very, very difficult for the brain is an extremely complex machine (one could say, bar aliens, it is probably the most complex object in the universe). But it's surely not "hard" in a fundamental level. We know the rules of physics applicable to physical systems like the brain. Technically we were able to image it at a very high resolution, and if we had massive computers to solve the equations, we could explain everything going on in the brain. It's difficult, but not "hard".
Yet this would bring us no closer to explaining the subjective conscious experience. Despite the fact that we know it exists, because we experience it, we have no idea how to measure it, how to explain, and why on earth it arises in this specific physical arrangement of atoms called the brain. A computer chip is also very complex, and integrates information. Is it conscious? We don't know and we will never know because any other consciousness other than ours is fundamentally inaccessible. In other words, this is a "hard" problem.