From Bitcoin University

In this video, I discuss the Bitcoin halving, and how the block subsidy gets cut in half every 210,000 blocks, or approximately every 4 years. The halving helps to strengthen the Bitcoin network, by weeding out inefficient miners, while leading us closer to the end of new BTC issuance and the final max supply of 21 million coins.

Unlike fiat currencies which are managed by central bankers, Bitcoin's monetary policy is programmatic and transparent. Everyone knows the rules of the system that they are opting into, and there is no room for insider trading and control.

The halving is also a good reminder of why it's important to keep Bitcoin's block size small. Limited block space helps to create a robust transaction fee market for Bitcoin that can help it to transition from a network mainly funded by new issuance (block subsidy) to a network that is funded fully by transaction fees.

This will become increasingly important as the block subsidy continues to get halved every 4 years. When a block is not completely full, it's still possible for people transacting to bid only 1 sat/vb. When blocks are full, that's when the transaction fee pressure ratchets up, and can help to replace lost revenue from the block subsidy declining.