>you get to look at any collected dirt

However, if you really don't want to look at it, you can always flip most DIY designs inside-out so the fans blow in and dust collects on the inside instead of the outside! This doesn't clean the room quite as efficiently, but if the appearance of dust is a major concern that should be a fix.

Yeah it’s functionally fine but I would opt to buy a more polished product for the above reasons. Probably would be great for a shop or similar, which is where I’ve done DIY purifiers myself. My personal favorite for cutting down on dust during home projects is a 20x20 furnace filter slapped on the intake side of a box fan. It requires zero extra parts or assembly.

Flipping the fans isn’t great because then you have to clean the fans, this is why draw-through is the standard configuration. Also many designs like this rely on negative pressure to seal properly or even stay together. You might just have the lid take off like a helicopter.