Regarding the long-term security of Bitcoin, there's an interesting topic: after the block rewards completely disappear around 2140, will miners continue to maintain the network?

The answer might be more optimistic than you think. According to industry experts' analysis, miners' income has never solely depended on block rewards. Block rewards and transaction fees are dual sources of revenue. As the former gradually decreases, the importance of the latter will continue to increase.

The key here lies in the design of the Bitcoin protocol itself — block space is scarce. Each block can only contain a limited number of transactions. When the network is busy, miners prioritize including transactions that pay higher fees.

You can think of miners as settlement providers. In financial systems, settlement providers handle payment processes and maintain ledger security, profiting from transaction fees. Bitcoin miners play a similar role — managing transactions, ensuring network security, and prioritizing transactions willing to pay. As block rewards diminish over time, this fee mechanism will become the primary source of income for miners.

Therefore, from an economic perspective, the long-term security of the Bitcoin network does not rely on perpetual block rewards but on the sustained fee revenue driven by this scarcity.