Physically assembling it is still fairly difficult. There’s the physical effort of wrangling a heavy heatsink or a huge graphics card into place while being gentle so you don’t bend or break any of the connectors. There’s plugging in all the cables in a tight space where you can’t always clearly see. There’s knowing which cable goes where when the labeling is small and all the cables look basically the same. There’s the challenge of knowing when a cable or a card is properly seated, knowing how much you can push to get something locked into place, without pushing too much and breaking it.

It’s harder than lego, but it’s not rocket surgery.