The canister is the unglamorous format that still cleans best per rupee. A mains motor is not constrained by battery weight or runtime, so a ₹11,000 canister delivers suction a ₹25,000 cordless cannot, holds it for as long as you want, and empties into a bin twice the size.
What you give up is convenience, and that is not a small thing — a canister has to be fetched, plugged in and dragged. Households that own only a canister clean less often than households that own only a stick. The strongest arrangement, and what we would recommend to most people, is a canister for the weekly deep clean and something light for daily passes.
One number decides more wrong purchases here than any other: the wattage on the box. Motor watts measure the electricity the motor draws, not the dirt it lifts. What lifts dirt is sealed suction — air watts, or kilopascals — and a well-sealed 1,000 W machine routinely out-cleans a leaky 2,000 W one. Where a brand publishes air watts or kPa we lead with it below; where a brand quotes only motor watts, that is usually because the honest figure is unflattering.