Wi-Fi is known to be slow, that's nothing new.
It was not obvious when Wi-Fi first appeared and most of us were connected to slow DSL connections at home. It was not obvious when many people still had 10Mbps Ethernet cards. But nowadays with optic fibres and widespread Gigabit Ethernet the difference is more pronounced.
It can also get worse if you're in a place where there are many other Wi-Fi networks, or if your computer is very far from the Wi-Fi access point. You also have different norms of Wi-Fi, with different speeds. 2-3Mbps sounds a bit slow even for Wi-Fi, I think you should rather sit around 10Mbps with "standard" Wi-Fi.
Your wifi connection is slow. This could be caused by many things:
* Bad signal quality between your router and your device.
* Your device (or your router) only supports 402.11B, which is about 2-3mbps. 402.11G is around 30mbps. N/AC is the newest wifi standard, capable of >300mbps.
* Your device and modem both support faster wifi but your device logged into the slower network for some reason.
Because Ethernet is faster and more reliable than wifi connections – especially if there are multiple conflicting wi-fi networks and/or a large distance or walls between the router and the device.
Cable is a lot faster and stable than wi-fi
Get new wifi router