I think I disagree with your base premise. Evolution isn't magic, and its existence doesn't mean that the human organism is perfect. Even if the process of evolution itself were perfect, for one thing it has nothing to say about the health of the organism after child-rearing is complete, whereas we probably care quite a bit what happens to us at that point.

There's also no reason to believe that every treatment has trade-offs. Many do, but the claim that every treatment necessarily causes some damage in order to treat other damage is provably false. The most straightforward example I can think of is treating something like a vitamin deficiency. But there are plenty of more significant treatments that don't do any appreciable harm while providing significant benefit. Removing a precancerous skin legion, for example.

All that said, my previous comment was not advocating for unnecessary treatments. It was advocating for taking all available information into account when deciding on a treatment plan (or lack thereof). The fact that many treatments involve trade-offs does not seem to me to be a counter-argument.