Many on Letsrun are young runners unaware of the reality of talent distribution; many are living in a running environment where only the top 5% are allowed, and they don't see that 95% as being serious...
So, they think I am slow with a PR of 16:44...but to get there I had to train hard for 20 years, averaging 80-100 miles per week, doing all the requiered intervals...
I did my PR in a collegiate track meet, at 35, where I finished not far from last. But in more than 400 road races I finished 85% of the time in the top 3 for my age group and 30% of the time on the overall podium. So if I am slow or nor serious by Letsrun users standards, it really means that the best on most road races are not. You can't say that.
As a coach for 25 years, I can tell you that many sub-16 runners are mostly very talented and not connected to people running outside of top clubs and school's program. I know, I coach one of these. And, yes, now 45 and at 18:00 for 5k I am out of the boys league and more challenged by the girls. But I still train harder than all of them and get ranking medals in many low key races.
I thinks 30 min is slow and 25 not fast. Under that it gets too over average. Elite starts somewhere in the "17:xx", where less than 5% of the people are.