Just to clarify, there's several types of wireless connections. Don't know about your system but here the most common wireless Internet is in the 4G mobile network, 5G gaining popularity. Back in the day there was other technologies used as well, basically a wired connection spread via a communication tower in close vicinity. I guess 'Fixed Wireless Internet' is a term to cover that.
4G and 5G both support Full Duplex which is very good for gaming as it fixes lost packets immediately when they occur instead of waiting for the whole load to arrive. Think of ordering a pallet full of items. If one item is faulty, half duplex will first check the entire pallet, then order it again. Full duplex will order the faulty item only right when it's found.
WiFi connecting your computer to the modem/router is only Half Duplex which makes it the weakest link.