I had pretty much every light switch and receptacle (minus the 3 I did myself) replaced in my house by two electricians 4 years ago. They charged me $400 and I was pretty happy with that. This seems excessive.

Wi-Fi is half duplex, Ethernet is full duplex. Wi-Fi cannot send and receive simultaneously and it cannot detect collisions.

If I have the choice between wireless and wired, I will take wired 100% of the time.