The reason why Aqara switch need hub is because it does not use wifi to communicate with the cloud server. It use zigbee to communicate with the hub and the hub will connect to your router then to the cloud server. The advantage of using zigbee will be reducing router load if you hv a lot of device (eg my hse i hv over 50 wifi switches and sensor). Furthermore zigbee use less power therefore good for battery power device like pir, door sensor etc. Powered zigbee device also act as repeater to create mesh newtwork. Wifi switch is simple to use as it does not need hub. Function wise it is the same as zigbee type. Pricing wise Aqara is expensive because it is propietary or closed system while the wifi switch you showed is open system (many suppliers can sell). Other open system like ewelink also is cheap.