> Sure, you'll get around 20 ms to the AP most of the time
If you're getting 20ms to your AP you're in a pretty poor environment or you need to upgrade away from 802.11b.
While on a video call on my laptop just now, while my home theater receiver is streaming internet radio over WiFi, while I've got a dozen other devices active on my WiFi, my average latency to my router is ~1ms. Running a speed test on my phone pushing pulling >500Mbit, my latency spiked...to 12ms!
Just like with the rest of this discussion about Bluetooth being bad, if you've got poor equipment and a poor environment you're gonna have a bad time. I have some cheap USB WiFi adapters which are terrible and struggle to get good performance. I don't use those except for temporary things or when I just don't care about network performance. I don't have issues with the Intel WiFi chips on my desktop or laptops or my Ubiquiti APs.