How far do you actually have to walk to get the last .01 km on an egg?
It is way more than 10m.
It's less the distance that matters, and more the fact that it only updates the distance you've traveled once every few minutes. So yeah, it can be annoying when an egg stops at 4.99 out of 5 km, then you have to keep going for like 5 more minutes before it finally hatches.
I've had my buddy distance go up by as much as .5 km in the time it took to give me that last .01 for an egg, so all that extra distance just went to waste instead of contributing to the next egg.