WiFi does or does not work.
The success of WiFi is based on a few things, mostly building layout and signal interference.
I lived in a 1100 sq-ft apartment and couldn't get a signal reliably in each room with a single router. I moved into a 2400 sq-ft house, and that same router (did I mention it's a $30 Netgear?) reliably covers the entire house, upstairs, main floor, basement, garage.
My point? Move out into the country. Go as far away from the city center as your preferred ISP offers service. Leave the crowded metro areas for good. They're a lost cause. Just like mobile, there's only so much shit you can cram into the airwaves before it's just too saturated.