i can kinda get how a glp-1 can be a miracle drug for weight: if we assume that simple molecular fixes to problems will eventually be found by evolution, then when we change our environment rapidly (e.g., with cheap bountiful calories) then this presents an opportunity for a miracle drug, since evolution will take some time to find the fix.

but for something like reducing disease infection, i find it a lot harder to understand why we don't create this naturally unless there is some equal-but-opposite cost that we'd incur, or if there is not actually as big of a benefit as we believe (or if this is all just colinear with the weight loss stuff).

note: i have no background in any of this and have no idea what i'm talking about