Putting the north at the top was an artifact of the need to select a standard orientation when the printing press enabled mass production of maps.

It was going to be north or south, thanks to the widespread existence of the magnetic compass at the time, and the printing press was invented by people in the north.

North was established earlier by European sailors as the north star is visible in the sky and is hugely useful for navigation, divining latitude etc. in the northern hemisphere. The coincidence of the north star and magnetic north as major navigational tools was really too hard to ignore.

Printing press and maps really started following the sailors and navigators knowledge and needs, where previously it was often religious or political (east at top facing jerusalem or 'oriented')

The word "orientation" literally means pointing towards the rising sun i.e. East.

What did maps from China look like around then? I assume they'd center their continent somehow