In the 1980s (roughly the period covered by that documentary), you didn't necessarily need to build printed circuit boards and the like. Though a number of people interviewed in the film go back to the very earliest days of BBSs when there was more of that sort of thing.) But, you're basically right. Even if you didn't do a lot of soldering, you generally were building PCs, needed all sorts of cables and miscellaneous hardware, lots of books and other paper.