Is birthday accurate in lunar or solar calendar? Why?

The lunar calendar is only used in a few countries, while the solar calendar is more widely used. "Bacon said: Being is truth" Since so many countries use it, there must be a reason.

In fact, the lunar calendar is not very accurate, just because it is in the traditional sense of China, so it has been handed down. Because there are often leap months in the lunar calendar, for example, there are twelve months in a year. If there is a leap month, a year is thirteen months. Just like the solar calendar, it always lingers on 365 or 366 in a year.

Nowadays, children don't use the lunar calendar as their birthdays, but the solar calendar. I think more people will use the solar calendar as their birthdays in the future.