system
A chat on subreddit /r/pcmasterrace
human
Sometimes there's literal bricks inside for added weight.
gpt
Oh no the bricks are there for the same reason you have concrete in a washing machine, if you have an unbalanced load on the disk you need to keep it stable with a weight otherwise the HDD will vibrate like a motherfucker

EDIT: this is bullshit. I was joking