comment: All of these problems are solved by not buying literally the cheapest blinds.
  Spend a bit more and you will get nice looks, better light blocking, good materials, and opening/closing mechanism that feel smooth.
  As for benefits over other blinds: you can control the amount of light that comes in.   You cannot evenly block out 50% of the light with a roller or traditional curtain.  You also don't need to wash them.