First, there are inanimate objects that look quite like those AI designs. Take a look at bone. Bird flight bone has fluted struts that look quite like that. #birdbones
Second, I think they should add parameters for ease of manufacture, ease of cleaning and human hand access. That engine block, for instance, would collect dirt rather well and be a great rat’s nest. It’s also very difficult to cast, which means it can’t be manufactured by normal means. It could be cast by lost-wax method in a one-use mold, but it would be a lot of work to remove the mold. And the surface wouldn’t be smooth like the one shown.
Third, human designs look the way they do because human engineers are intensively schooled to design parts that can be manufactured at reasonable cost within the methods available to us. Simpler shapes are also easier to manage for impact on other parts. A cylinder can turn on a lathe. Balance it reasonably well, and it can be turned to thread it and finish parts of it. Etc.