These are cardboard magazine files, intended to sit on a shelf and make organizing your magazines easy. I bought two sets. They went together easily. They look really pretty on the selves.
There is a trick to making these up. Following the instructions help, but they don't tell you to push the pieces in until they fall into place and interlock and then push them back where they belong. But once you get the hang of it, you don't need to tape anything.
I haven't tried to carry these around filled. That isn't what they are intended for. They are intended to sit on a shelf and rarely get moved. If you need to fill a box like this and move it from place to place you need to get something a lot more expensive.
I've used file boxes like these for decades successfully. It is time to replace some of them because after 20 years they tend to get a bit yellow looking. They do the job they were designed to do, and they do it well.