Why did Bitcoin’s creator set a hard cap of 21 million coins?
I think it was a well mathematical calculated choice.
Can't remember the approach now, but the rewards and number of blocks where put into consideration. The hard cap simply makes it limited, even though it is technically possible to increase it, but a consensus is needed for that, which might not be easy.
Here is what I found...
https://github.com/bitcoin/bitcoin/blob/master/src/consensus/amount.h?ref=blog.lopp.net/** No amount larger than this (in satoshi) is valid.
*
* Note that this constant is *not* the total money supply, which in Bitcoin
* currently happens to be less than 21,000,000 BTC for various reasons, but
* rather a sanity check. As this sanity check is used by consensus-critical
* validation code, the exact value of the MAX_MONEY constant is consensus
* critical; in unusual circumstances like a(nother) overflow bug that allowed
* for the creation of coins out of thin air modification could lead to a fork.
* */
could anything lead to changing Bitcoin’s 21 million supply limit?
Not sure though, but if there is, it must be agreed upon.