Earlier quoted context omitted.
To change the algorithm, all three of miners, users, and nodes would have to agree to the change. If there is any disagreement, the network continues running under current consensus rules. In fact, a majority of miners did try to strongarm a fork 5 years ago, and they failed, because the users did not agree. There was even been a book written about it. https://www.amazon.com/Blocksize-War-controls-Bitcoins-proto... I…
While the block reward remains high in USD terms, I think you’re right with regards to the power balance. But if the reward falls low enough—which very well might happen, if the price of Bitcoin stagnates and if transaction fees stay low—then there won’t be enough miners to secure the network without some kind of change to the algorithm. The Bitcoin Cash fork happened when prices were rising and the inflation rate wa…
The security issue with less miners is the whole 51% attack, but even with a substantial drop in miners, it would still mean the attacker would need many thousands of nodes. Seems like that kind of energy and spend would be more profitable mining.