What are the downsides of robot vacuums?

Robot vacuums cannot move objects, so furniture, toys, charging cables, pet messes, socks, and loose rugs can block or damage the unit, causing repeated passes or stoppage. Their navigation varies by cost: basic models use bump sensors, mid-range use infrared, and premium models employ LiDAR and AI cameras, yet even the most advanced units struggle with cables and lightweight rugs. Cleaning effectiveness depends on surface type; robot vacuums handle surface debris on hard floors well but struggle to agitate and lift dirt from thick carpets, and raised rug edges or doorways can trap the unit and reduce suction.