They might be. Depends on where they live and their terrain and their fitness and position. In general, you have to be toward the pointy end to ride 20+ averages, but that's less true in very flat areas or with a group.
Here are a few 20+ rides:
https://www.strava.com/activities/1132203252/analysis(flat, Z3 effort, so pretty fast)
https://www.strava.com/activities/897899841(2 other guys, quite hilly)
https://www.strava.com/activities/917364123https://www.strava.com/activities/952238163https://www.strava.com/activities/1104935098You're right though in the sense that most rides aren't averaging over 20, because most guys aren't sitting on the sustained power for those kinds of rides. Exception being very flat areas, when you start seeing well under 50ft/mile of elevation, averaging 20mph becomes more commonplace.
22-23 is pretty doable for moderate durations for many guys. Averaging that for a ride over an hour? Yea....not so much. I rarely see that outside of group situations. When I do, it's a higher level, larger TT guy hitting a few hours of SS or something.
25 for anything above 15' gets tough on a road bike. You've got solid position and good power if you can average 25mph for 30+ mins solo (assuming no tailwind) in regular gear.