Endurance sports are quite accessible and don't require that much time, effort, or talent to get way better than the vast majority of people, it's just consistency.
FWIW, that now includes me, as a 62 year old. I can hit 6:30 pace for 400m, but find it almost impossible to get under 10:0x for a mile. And that's even after 6 months of training for a 50 mile trail race.
Considering that you can still do a decent sprint over 400m and have the endurance for ultra marathon distances at lower pace, it sounds a bit odd.