It's more nuanced than that. Unique parts made to fit specific applications can clearly perform better, but that doesn't mean I'm in favor of them in all contexts. Rather, I'm observing that the reason we don't use them for things like desk lamps, instead using mostly generic parts, is because of our cognitive limitations, which we cope with through specialization and generic parts with loosely-coupled, independent designs. This is a form of "dividing and specializing design", which is what alganet was saying people shouldn't do.

I am not in favor of ignoring those cognitive limitations. That wouldn't make the limitations go away; it would only keep us from taking measures to cope with them, such as dividing and specializing design into modular generic parts.