There are lots of things I don't know about evolution. There are lots of things we as a civilization still don't know about it. I could ask a question about some metabolic process in some obscure worm species evolved, and there's a reasonable chance a scientist could give me an answer. Or apply for a grant to find out. There's always more to be found out, and too much for any one person to know it all.
"Intelligent Design," on the other hand, is quite different on that front. It seems I know pretty much everything civilization knows about ID. I haven't seen anything new on the ID front in all the time I spent looking at it or asking questions about it. Whenever I ask a question about the underlying logic, I never get a straight answer, only predictable fallacies. Whenever I ask a question about some feature, the answer's always "Magic man done it!" and no one ever knows how or why the designer allegedly did it, or how they reached that conclusion. When we're looking for new things, ID never tells us what we can expect to find.
Evolution, on the other hand, can give us an idea of what kinds of fossils we'll find where, and how deep. If we don't know how a feature evolved, we can use the principles to form a hypothesis and look for information to verify or refute the hypotheses we form. With Intelligent Design, anything that comes out sloppy or wrong is met with "the designer meant to do that." ID can explain any result, or predict anything. Therefore it can predict nothing. It's like cases of "psychics" predicting a good outcome for someone with a terminal disease: If they make it, they can take credit. If they die, they just say they saw them being fine in heaven or wherever. One "prediction" can explain two opposite results and be considered a "success."
That's why ID is worthless. It has the hubris to pretend to understand everything, and offers nothing new to learn.