Yes - it'll take companies, universities, etc. some time to update their WiFi (Apple knows this, and will include WiFi 6 when it becomes a feature of the chips they're using and not before).
Even high-end campus and corporate WiFi is as likely 802.11n as 802.11ac (I just checked the network I'm on at a major, well-known university with a significant budget, and this building is 802.11n - 216 Mbps). I'm sure we have 802.11ac in some places - I feel like I've gotten some really fast upload and download speeds at times. They simply don't change access points all that frequently (they buy the latest stable option when they do).
Public WiFi is often REALLY old, overcrowded or deliberately slowed down. If it's not, the pipe connected to it is often not all that fast.
The only case where WiFi 6 will be adopted quickly is small offices and homes who change routers quickly - and a small subset of those have a gigabit pipe to take advantage of it. If you work for a small, high-end animation studio that's always got the latest tech - sure... If you have gigabit + fiber at home, you can buy a router... Everyone else is at the mercy of some upstream element.