> that's how you explain things after the fact
I agree, that's what I said "if what your parent comment suggests is true"
In fact, said parent comment said "It might have been a mere speculation but it kind of makes sense"
I agree with you that there is no predictive power in explaining things that way (indeed, what I said is speculation, hence why I worded it in the conditional), but that was not what I was responding to. I was only responding to the "design" part of your comment.
That being said, evolution does make predictions which have been confirmed. Notably Darwin's long-nosed moth. Here's a list of more predictions[1]