How to answer the "because evolution" response to hard problem? Evolution doesn't provide the best/only answer to a challenge. It was just the first good answer to come along; whatever that happened to be. Anything that improves on the previous solution will be accepted. So when someone says "because evolution" to the hard problem, I think it is like they are asking: "Why can't the way it currently exists be one of the possible solutions to the challenge?"
Our brain includes many different parts. Some of those parts need to compete with each other; some have no need for competition. For example, a beating heart is always superior to a non-beating heart. So our brain does not bother to give us conscious control over our heartbeat.
Other areas of the brain need to compete with each other. Fear and hunger, for example. Sometimes the best strategy for life is to eat a slice of pizza. At other times, the best strategy for life is to run from a Grizzly bear. If our brain cannot sustain fear and hunger at the same time, then how does it break the tie? What does our brain use to settle these competing urges?
One solution would be an administrative center to the brain (our consciousness). Let's say you are having a picnic. Eating a slice of pizza alone in the woods, as one normally does. The pizza is satisfying your hunger when a Grizzly bear walks out from behind the bushes. All of a sudden you have lost your sense of hunger. Your consciousness is reprioritizing different areas of the brain. Your fear center is being amped up and made more active. The area that controls hunger is being inhibited and put on a back burner. If this reprioritization helps you survive, then the conscious brain has proven its evolutionary worth.
The hard problem could be summarized by asking: "Why doesn't this administrative reprioritizing of different brain areas happen in the dark? Why can it be experienced?"
I would have two responses to that question:
1) You could say it does happen in the dark. The world does not experience your consciousness. As humans, we spend our entire lives struggling to guess what kind of conscious thought patterns are bouncing around in someone else's head. We do not get a chance experience the conscious thought of others firsthand. In that sense, the conscious mind is carrying on in the dark without anyone taking notice.
2) Why can't an administrator have a larger image of all the tasks taking place, if said image helps them better complete their work? As individuals, each one of us is one of those summarized images. A centered perception sensing communication from other areas of the brain. An area of the brain whose purpose it is to see the brain itself. If the brain functions more efficiently when it sees itself, then the assumption that it should "take place in the dark" is incorrect. Maybe there was no hard problem thousands of years ago. But the human brain tried looking in a mirror once, and things have worked out better ever since. We experience our consciousness because not every kind of brain function can take place in the dark. How exactly do you propose that the conscious center of the brain be aware of other areas of the brain without becoming conscious in the process? What is the obvious alternative version of inter-brain awareness, if you are not in favor of the strategy that nature has chosen in this instance?
It makes you wonder ... are you the only conscious process taking place inside your brain? Maybe there are more consciousnesses happening in other areas of your brain. They could have been there your entire life. You, blissfully unaware of the other yous; and them, blissfully unaware of you. Each consciousness assuming themselves to be in the driver's seat, yet curiously lacking in total self-control.