Recently, Jamie Dimon made an interview with CNBC where he stated that "bitcoin is a ponzi scheme" and then asked "I'll just challenge the group to one other thing: how do you know it ends at 21 million?" but that was october 2021 and now in Davos, he's currently with the same speech.

As Jameson Loop stated, it's just 5 lines of codes, like this since line 1068:

CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams)

{

int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;

// Force block reward to zero when right shift is undefined.

if (halvings >= 64)

return 0;

CAmount nSubsidy = 50 * COIN;

// Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years.

nSubsidy >>= halvings;

return nSubsidy;

And the second one: it's up to you. Yes, you, the one who's reading this. No joke. With your node, you'll verify every transaction, contribute to secure the network and most important of all thing, you are directly contributing to decentralize bitcoin because you're verifying ~10 minutes that only exists 21 millions bitcoin. At Reddit, Peter Wuillie stated:

Look at it another way: if only a few large players in the Bitcoin ecosystem were running full nodes, it only requires a malicious intent, or an attack/threat against them, to change the system's rules, as nobody else is validating. Doing transactions in the Bitcoin ecosystem helps the Bitcoin currency. Running a full node helps the network. Using a full node helps you and the ecosystem reduce the need for trust.

If you want to play with the blockchain finally, here's some tools you can use.