the typical 2.4GHz path loss, in a residence, is on the order of 60-100dB. Start with +15dBm or so, subtract a path loss (distance and walls/floors), and the RSSI is at -80 or so. Unless you're in the same room with the WiFi access device. The client device probably doesn't have +15dBm, but that's just a few dB as compared to the free space + wall/floor loss.
The point is, I content, the throughput/speed at less than 30 or 40dB of path loss/attenuation is arguably irrelevant for most real-world path length and obstructions.