By way of that, you probably know that Iran gets its name from around World War II as “land of the Aryans”, to show their solidarity with Hitler. Just a side note.
I didn’t know where the name Iran came from. I knew it used to be called Persia but didn’t know where Iran came from.
I also don’t know why Peking became Beijing, or why Bombay became Mumbai, or why Siam became Thailand.
IIRC, irani, like aryani is a word that goes back to ancient Indo-European before the Persian/Sanskrit split. Iran as a name for the people goes way back, although pars,persia,farsi,etc. are also seen.
Only if Hitler was around in 600 BC. Cyrus referred to himself as the King of Iran and non-Iran. So did his successors down to the Muslim conquest.
IOW, the natives always called their country Iran. Persia was a name given to them by their Greek enemies.