I am a hobby jogger, so this is all about me. What do I think is impressive?
At the local, random, charity 5k:
Young guy: under 17
Young female: under 20
40ish guy: under 19
40ish female: under 21
55+ guy: under 20
55+ women: yet to see one run under 25… not impressed yet
At my daughters D1 track meets:
Guys: probably 14:15 or better
Girls: under 17
What does NOT impress me? Slow runners (like 5 hour marathoners) bragging that they compete in multiple marathons/half marathons each year, and they will give the names of each even though you do not ask. Even though I am a hobby jogger, I am not impressed that you pay $$$ to run in big city marathons to finish in the bottom 10%.