But they're not!
Most problems people get themselves into while assembling Ikea-stuff -in my experience- is that they think it looks simple enough and just begin without 'reading' the instructions.
They invariably get into trouble at some point and then refer to the instructions. This is the point when they realise they are totally lost -usually because they did things in the wrong order (as they didn't follow instructions) and are not able to continue assembling because things that interlock cannot... mostly because they weren't assembled in the right order...
Best job-skill-test ever: assemble a piece of Ikea-furniture from a flat-pack! It shows if people are able to read simple instructions and
if they are capable of following instructions, it shows if people have patience and if they have too many thumbs