The products we use had designers. Since many of them, such as planes, mimic what is found in nature, such as birds, then those things found in nature must have also had a designer (please watch JW.org's video: What Your Peers Say—Belief in God).
arcording to the logic of the video everything complex needs a designer but the designer himself must be complex so there must be a designer_2 that desgned the designer. -next we need designer_3 to design desgner_2 ...=> endless chain of designers
We are mimicking millions of years of natural selection. Your argument begs the question why the object we mimic has to have similar specific qualities like the object we are building. Example: I made this painting using oil colors, therefore your picture I mimicked must be made out of oil too.
Merely because something is complex does not mean that it did not form naturally. The fact that we can provide models of them forming naturally, then observe how closely these models hold to reality is sufficient evidence to disprove that. The "watchmaker" argument is entirely fallacious.