@Ponderable saidIn fact, some evolutionary trends make for worse conditions for the descendants.
A very general reamrk: A lot of people don't undersatnd the theory of evolution:
Evolution has no "aims".
So eveolution doesn't "want", "plan" or "design" anything.An organ has a function not because it was "intended" but because it proved to be useful by the stresstest of live.
And yes we still have structures in our body, which don't seem to have any "use" that would be expected by the theory of evolution. Some might proove to be an advantage some won't.