Why 21 million #Bitcoin?

What was Satoshi's thought process during the early stages of Bitcoin's design in 2008?

A recent release of private emails with Satoshi by Sirius (

@npub1g53mukxnjkcmr94fhryzkqutdz2ukq4ks0gvy5af25rgmwsl4ngq43drvk

) sheds light on Satoshi's reasoning regarding supply and issuance.

https://stacker.news/items/458544