Why Are Transaction Fees Becoming Increasingly Important for Miner Revenue?

Transaction fees are becoming more important because the block reward subsidy (the newly minted coins) is periodically halved through events like the Bitcoin halving. As the subsidy decreases, fees must make up a larger percentage of the total block reward to keep mining profitable.

In times of high network congestion, transaction fees can temporarily exceed the block subsidy, significantly boosting miner revenue and ensuring the long-term economic security of the network.