This is a nice, thought provocative article.

I also read the comments and agree with most of Tony's comment. "Damned if you do, damned if you don't. From what I understand, you simply cannot get it right for everyone. However you can try to come close by starting with research. Depending on the market you're in and the product involved; research involves resources and money. And these aren't always available.

I think the necessity of documentation depends on some variables. In the end documentation needs to serve the user to reach their specific goal with the product they are using (whether it be software, a car, a toaster or ....).

There are many different type of users, with different learning techniques (some read docs, others fiddle about), different skill level(including self-overestimation) , different amount of patience(deadlines) and different personality traits(tempered). And of course with different expectations of the product they are about to use or set up.

And there are many type of products. Simple products that solve a single "problem" and complexer products that let you do more things. And there is Word of Mouth: They told be "product x" will do this, I read that "product y" would solve that...

So I think user research including testers helps you to build a better product and good documentation (or a unboxing, installation video) compliments the product. The happy experience adds to the brand image.