Respectfully, I think you may be downplaying a lot of how the scientific processes is supposed to work.
Back in ye olden times, a lot of mental illness was just assumed to be Satan trying to get to the patient and draw them away from God. Things like depression or OCD were treated with spiritual care rather than actual treatment. I’m not saying that trying to help someone through prayer is bad, but back then people didn’t understand the underlying mechanism and thus were treating symptoms and not the disease.
Fast forward a few centuries and now mental health research is a well-developed and well understood area of medicine and health. One could go and be diagnosed and can successfully treat it with medicine or other techniques, thus reducing the impact that the disease had on their life.
So, why are we able to treat mental illnesses much more effectively today than years ago? The underlying mechanism of science is an assumed natural cause. A scientist would look at a mental illness and think, “I wonder what goes on in the brain that causes this to occur.” The same can go for lightning: people used to think that lightning was an effective means for God to enact punishment onto sinners. When Ben Franklin invented the lightning rod, people believed that he was intervening in God’s work. However, by assuming that lightning was something natural rather than Divine, Ben Franklin went about inventing a method of channeling the energy into one place to prevent buildings from being struck and caught on fire.
Applying this to the theory of evolution, a scientist has to develop a theory to explain why life looks like it does now and how life today relates to the fossils we find in ground. Unfortunately, saying “life looks like this because God made them that way” isn’t a valid explanation because it doesn’t give us much to glen and actually apply. If we just said that mental illness was God testing people, then we wouldn’t have attempted to try and treat it because if this was the will of God then who could possibly tell him otherwise? If we just said that lightning was God punishing sinners, then we wouldn’t have developed means to protect buildings from lightning because burning those buildings was God’s will. So, if we just said that all life looks like this today because God made then that way, we wouldn’t try to examine how environmental factors can influence life.
What we need to remember is that we live in a Universe that was given free will. If God simply decided to puppet every non-human decision, then what purpose did He have in creating a Universe that’s just an extension of Himself? How could humans have free will if every environmental factor we encounter was instituted by God for a specific reason?
As an Evolutionary Creationist, I look at Creation this way: God, knowing what the ultimate outcome of the Big Bang would be, allowed Creation to go on and do its own thing. For example, when photosynthesis first began on Earth, the sheer amount of oxygen in the atmosphere began to literally corrode single cell organisms. However, instead of simply dying off, those little critters were forced to learn to utilize oxygen as fuel. Oxygen can release vastly more energy than the fuel they used before, which allowed for these microorganisms to become more complex and thus complex life (like us) became possible. Why would God essentially play Chess against Himself in this manner? Why would God directly create organisms that make oxygen, and then afterwards create organisms that use oxygen? Why did he bother making the original organisms in the first place? Why did he waste his time on these organisms if they just were replaced anyway? If we apply the theory of evolution instead, we see life genuinely learning to make the best of its situation.
With the theory of evolution in hand, we can understand a great deal more about nature. Why do whales have tiny hind legs in their skeletons? Evolution would tell us that, long ago, they used to be on land. Now, we can learn not only what conditions would have caused this but also try to figure out what other animals whales are related to. Evolution also helps us better understand how certain species developed over time. Why did some dinosaurs, such as Tyrannosaurus Rex, have relatively small arms? Well, evolution tells us that as T-Rex invested more of its energy into a larger head for hunting, it required less from its arms.