A few days ago on BitcoinTalk someone speculated that mining BTC it will no longer be profitable in the future. The analysis begins with the observation that whoever manages to extract the block will currently earn about $ 300,000.
BTC mining in the Future and rules
Because each block contains just under 3,000 transactions, they collect the equivalent of $ 100 for each transaction they confirm by placing it in the block.
So the author wonders whether, in the future, when miners stop being rewarded with BTC bonuses in each block, they agree to less than $ 100 per transaction, or will users agree to pay a $ 100 fee?
Assuming most users might be willing to pay $ 2 for transaction fees, miners’ income would be only about 2% of what it is today, forcing them to reduce energy consumption and thus hashrate by 98%.
At this point, the author wonders whether such a low hashrate could reduce the security of the BTC network, as it could be exposed to more than 51% of the attack.
The limit of 3,000 transactions is due to the fact that currently each bit of BTC blockchain can have a maximum size of 1 MB. This size is expandable. In 2017, there was a proposal to expand it, but it failed until the last minute.
It is very likely that sooner or later this limit will be extended, which will also significantly increase the number of transactions verified per block.
It should be borne in mind that the block time, ie. the average time that elapses between the block acknowledgment and the time of generating the next block remains around 10 minutes.
It is not necessary for one transaction recorded on the blockchain to contain only one amount sent from one sender to one recipient. So-called mixing systems aggregate many different transactions into one aggregated transaction, which is recorded on a blockchain.
Thus, it is possible that, in total, the fees paid for one aggregated transaction are also much higher than the $ 2 assumed by the author of the contribution. Hash hash reduction is possible anyway, but will hardly be 98%. If, instead, the block size increases a lot in the future, it is even possible that this reduction will be minimal.
The fact that the miner’s premium is halved every two years gives the network enough time to adapt to any problems that may arise. If any appear, there will probably be plenty of time to intervene.
The BTC Protocol is not modifiable by individual parties. Nevertheless, it remains modifiable if there is broad agreement on the changes, as happened in August 2017 with the introduction of SegWit, or a few months ago with the approval of Taproot.
These changes are not hard forks, but compatible upgrades and block resizing may instead require a hard fork with string splitting. But it is likely that the global BTC community would accept such a change if necessary.