Today, most Bitcoin miners are in the mining business to generate profits. The number of people mining — and thereby securing the Bitcoin network — for ideological reasons is likely to be negligible, especially when looked at in percentage of hashrate. Thus, the most important factor for Bitcoin mining is the block rewards, which are paid to miners for expending energy on finding hashes (finding a nonce to be specific) and for adding a new block to the Bitcoin blockchain.
Currently, the block reward is 6.25 BTC per block. The block reward is cut in half every four years. The next
halving is happening in 2024 (the
countdown clock). Additionally, miners adding a block to the blockchain also receive all the transaction fees contained in a block. Currently, transaction fees only make up a
small part of the total rewards paid to miners.
As miners have to pay their own expenses (hardware, electricity) in fiat currency, the current Bitcoin
(BTC) price in USD is of utmost importance for every mining operation. Should the price of Bitcoin collapse, mining is likely to become unprofitable for most miners, at least in the short term. Block rewards and transaction fees are determined by the network and are the same for all miners. Thus, they cannot be optimized.