When somebody is 0 years old, they’re in their first year of their life as well.

Whose age exactly are we recording here though? We're counting years since an event (it is now the 2025th year since the event), not somebody's or something's age (the event is 2024 years old).

I seriously do not see how not having a 0th year is comparable to a bug and how having a year 0 would be in any way "better". It doesn't matter, outside of the occasional confusion among people who really aren't affected much by the exact number the current year has as long as everybody agrees.