The article is specific to software engineers, and perhaps it's accurate within that discipline. The field is incredibly broad—ranging from writing small support scripts to engineering massive distributed systems—so it's plausible that a self-taught engineer could excel in certain areas. However, I don't believe this holds true, or is even feasible, for other engineering disciplines. In those fields, earning an engineering degree is typically a prerequisite. After that, you're free to self-teach and explore further, but without that formal foundation, it's difficult to progress meaningfully.

Side note: I think the term self-taught is often misused. Very few people are truly self-taught in the sense of starting from a blank slate and independently mastering a subject without any guidance. What the article refers to as self-taught is really just informal education—learning through blogs, tutorials, bootcamps, or YouTube University.